Association of sounding reference signal (srs) with multiple frequency-domain staggered random access channel (rach) resources

ABSTRACT

Disclosed are techniques for wireless communication. In an aspect, a user equipment (UE) receives, during a first state, a configuration of a sounding reference signal (SRS) resource or SRS resource set, obtains an association between the SRS resource or SRS resource set and a group of random access channel (RACH) resources, and transmits, while outside the first state, a group of RACH signals using transmission properties based on the association between the SRS resource or SRS resource set and the group of RACH resources, wherein the group of RACH resources spans a plurality of adjacent frequency resources over a single time resource, or the group or RACH resources spans the plurality of adjacent frequency resources over a plurality of time resources.

CROSS-REFERENCE TO RELATED APPLICATION

The present Application for Patent claims priority under 35 U.S.C. § 119to Greek Patent Application No. 20190100544, entitled “ASSOCIATION OFSOUNDING REFERENCE SIGNAL (SRS) WITH MULTIPLE FREQUENCY-DOMAIN STAGGEREDRANDOM ACCESS CHANNEL (RACH) RESOURCES,” filed Dec. 5, 2019, which isassigned to the assignee hereof and expressly incorporated herein byreference in its entirety.

BACKGROUND OF THE DISCLOSURE 1. Field of the Disclosure

Aspects of the disclosure relate generally to wireless communications.

2. Description of the Related Art

Wireless communication systems have developed through variousgenerations, including a first-generation analog wireless phone service(1G), a second-generation (2G) digital wireless phone service (includinginterim 2.5G and 2.75G networks), a third-generation (3G) high speeddata, Internet-capable wireless service and a fourth-generation (4G)service (e.g., Long Term Evolution (LTE) or WiMax). There are presentlymany different types of wireless communication systems in use, includingcellular and personal communications service (PCS) systems. Examples ofknown cellular systems include the cellular analog advanced mobile phonesystem (AMPS), and digital cellular systems based on code divisionmultiple access (CDMA), frequency division multiple access (FDMA), timedivision multiple access (TDMA), the Global System for Mobilecommunications (GSM), etc.

A fifth generation (5G) mobile standard, referred to as New Radio (NR),calls for higher data transfer speeds, greater numbers of connections,and better coverage, among other improvements. The 5G standard,according to the Next Generation Mobile Networks Alliance, is designedto provide data rates of several tens of megabits per second to each oftens of thousands of users, with 1 gigabit per second to tens of workerson an office floor. Several hundreds of thousands of simultaneousconnections should be supported in order to support large sensordeployments. Consequently, the spectral efficiency of 5G mobilecommunications should be significantly enhanced compared to the current4G standard. Furthermore, signaling efficiencies should be enhanced andlatency should be substantially reduced compared to current standards.

SUMMARY

This summary identifies features of some example aspects, and is not anexclusive or exhaustive description of the disclosed subject matter.Whether features or aspects are included in, or omitted from thissummary is not intended as indicative of relative importance of suchfeatures. Additional features and aspects are described, and will becomeapparent to persons skilled in the art upon reading the followingdetailed description and viewing the drawings that form a part thereof.

In an aspect, a method of wireless communication performed by a userequipment (UE) includes receiving, during a first state, a configurationof a sounding reference signal (SRS) resource or SRS resource set,obtaining an association between the SRS resource or SRS resource setand a group of random access channel (RACH) resources, and transmitting,while outside the first state, a group of RACH signals usingtransmission properties based on the association between the SRSresource or SRS resource set and the group of RACH resources, whereinthe group of RACH resources spans a plurality of adjacent frequencyresources over a single time resource, or the group or RACH resourcesspans the plurality of adjacent frequency resources over a plurality oftime resources.

In an aspect, a method of wireless communication performed by atransmission-reception point (TRP) includes receiving, from a UE, an SRSon an SRS resource or SRS resource set, and receiving, from the UE, agroup of RACH signals having transmission properties based on anassociation between the SRS resource or SRS resource set and a group ofRACH resources on which the group of RACH signals were received, whereinthe group of RACH resources spans a plurality of adjacent frequencyresources over a single time resource, or the group or RACH resourcesspans the plurality of adjacent frequency resources over a plurality oftime resources.

In an aspect, a UE includes a memory, at least one transceiver, and atleast one processor communicatively coupled to the memory and the atleast one transceiver, the at least one processor configured to:receive, during a first state, a configuration of an SRS resource or SRSresource set, obtain an association between the SRS resource or SRSresource set and a group of RACH resources, and transmit, while outsidethe first state, a group of RACH signals using transmission propertiesbased on the association between the SRS resource or SRS resource setand the group of RACH resources, wherein the group of RACH resourcesspans a plurality of adjacent frequency resources over a single timeresource, or the group or RACH resources spans the plurality of adjacentfrequency resources over a plurality of time resources.

In an aspect, a TRP includes a memory, at least one transceiver, and atleast one processor communicatively coupled to the memory and the atleast one transceiver, the at least one processor configured to:receive, from a UE, an SRS on an SRS resource or SRS resource set, andreceive, from the UE, a group of RACH signals having transmissionproperties based on an association between the SRS resource or SRSresource set and a group of RACH resources on which the group of RACHsignals were received, wherein the group of RACH resources spans aplurality of adjacent frequency resources over a single time resource,or the group or RACH resources spans the plurality of adjacent frequencyresources over a plurality of time resources.

In an aspect, a UE includes means for receiving, during a first state, aconfiguration of an SRS resource or SRS resource set, means forobtaining an association between the SRS resource or SRS resource setand a group of RACH resources, and means for transmitting, while outsidethe first state, a group of RACH signals using transmission propertiesbased on the association between the SRS resource or SRS resource setand the group of RACH resources, wherein the group of RACH resourcesspans a plurality of adjacent frequency resources over a single timeresource, or the group or RACH resources spans the plurality of adjacentfrequency resources over a plurality of time resources.

In an aspect, a TRP includes means for receiving, from a UE, an SRS onan SRS resource or SRS resource set, and means for receiving, from theUE, a group of RACH signals having transmission properties based on anassociation between the SRS resource or SRS resource set and a group ofRACH resources on which the group of RACH signals were received, whereinthe group of RACH resources spans a plurality of adjacent frequencyresources over a single time resource, or the group or RACH resourcesspans the plurality of adjacent frequency resources over a plurality oftime resources.

In an aspect, a non-transitory computer-readable medium storingcomputer-executable instructions includes computer-executableinstructions comprising at least one instruction instructing a UE toreceive, during a first state, a configuration of an SRS resource or SRSresource set, at least one instruction instructing the UE to obtain anassociation between the SRS resource or SRS resource set and a group ofRACH resources, and at least one instruction instructing the UE totransmit, while outside the first state, a group of RACH signals usingtransmission properties based on the association between the SRSresource or SRS resource set and the group of RACH resources, whereinthe group of RACH resources spans a plurality of adjacent frequencyresources over a single time resource, or the group or RACH resourcesspans the plurality of adjacent frequency resources over a plurality oftime resources.

In an aspect, a non-transitory computer-readable medium storingcomputer-executable instructions includes computer-executableinstructions comprising at least one instruction instructing a TRP toreceive, from a UE, an SRS on an SRS resource or SRS resource set, andat least one instruction instructing the TRP to receive, from the UE, agroup of RACH signals having transmission properties based on anassociation between the SRS resource or SRS resource set and a group ofRACH resources on which the group of RACH signals were received, whereinthe group of RACH resources spans a plurality of adjacent frequencyresources over a single time resource, or the group or RACH resourcesspans the plurality of adjacent frequency resources over a plurality oftime resources.

Other objects and advantages associated with the aspects disclosedherein will be apparent to those skilled in the art based on theaccompanying drawings and detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are presented to aid in the description ofvarious aspects of the disclosure and are provided solely forillustration of the aspects and not limitation thereof.

FIG. 1 illustrates an example wireless communications system, accordingto various aspects of the disclosure.

FIGS. 2A and 2B illustrate example wireless network structures,according to various aspects of the disclosure.

FIGS. 3A to 3C are simplified block diagrams of several sample aspectsof components that may be employed in a UE, a base station, and anetwork entity, respectively, and configured to support communicationsas taught herein.

FIGS. 4A and 4B are diagrams illustrating examples of frame structuresand channels within the frame structures, according to aspects of thedisclosure.

FIGS. 5 and 6 illustrate example random access procedures, according toaspects of the disclosure.

FIG. 7 illustrates the different RRC states in NR, according to aspectsof the disclosure.

FIG. 8 is a diagram of an example positioning procedure between a UE andtwo TRPs, according to aspects of the disclosure.

FIG. 9 is a graph illustrating the different preamble lengths andformats.

FIG. 10 is a diagram of an example allocation of RACH occasions (ROs) inthe time domain.

FIGS. 11A to 11D illustrate various examples of RO allocations in thetime and frequency domains.

FIG. 12 is a diagram of an example positioning session between a UE andtwo TRPs, according to aspects of the disclosure.

FIGS. 13A to 13C are diagrams of example configurations of ROs,according to aspects of the disclosure.

FIGS. 14 and 15 illustrate example methods of wireless communication,according to aspects of the disclosure.

DETAILED DESCRIPTION

Aspects of the disclosure are provided in the following description andrelated drawings directed to various examples provided for illustrationpurposes. Alternate aspects may be devised without departing from thescope of the disclosure. Additionally, well-known elements of thedisclosure will not be described in detail or will be omitted so as notto obscure the relevant details of the disclosure.

The words “exemplary” and/or “example” are used herein to mean “servingas an example, instance, or illustration.” Any aspect described hereinas “exemplary” and/or “example” is not necessarily to be construed aspreferred or advantageous over other aspects. Likewise, the term“aspects of the disclosure” does not require that all aspects of thedisclosure include the discussed feature, advantage or mode ofoperation.

Those of skill in the art will appreciate that the information andsignals described below may be represented using any of a variety ofdifferent technologies and techniques. For example, data, instructions,commands, information, signals, bits, symbols, and chips that may bereferenced throughout the description below may be represented byvoltages, currents, electromagnetic waves, magnetic fields or particles,optical fields or particles, or any combination thereof, depending inpart on the particular application, in part on the desired design, inpart on the corresponding technology, etc.

Further, many aspects are described in terms of sequences of actions tobe performed by, for example, elements of a computing device. It will berecognized that various actions described herein can be performed byspecific circuits (e.g., application specific integrated circuits(ASICs)), by program instructions being executed by one or moreprocessors, or by a combination of both. Additionally, the sequence(s)of actions described herein can be considered to be embodied entirelywithin any form of non-transitory computer-readable storage mediumhaving stored therein a corresponding set of computer instructions that,upon execution, would cause or instruct an associated processor of adevice to perform the functionality described herein. Thus, the variousaspects of the disclosure may be embodied in a number of differentforms, all of which have been contemplated to be within the scope of theclaimed subject matter. In addition, for each of the aspects describedherein, the corresponding form of any such aspects may be describedherein as, for example, “logic configured to” perform the describedaction.

As used herein, the terms “user equipment” (UE) and “base station” arenot intended to be specific or otherwise limited to any particular radioaccess technology (RAT), unless otherwise noted. In general, a UE may beany wireless communication device (e.g., a mobile phone, router, tabletcomputer, laptop computer, tracking device, wearable (e.g., smartwatch,glasses, augmented reality (AR)/virtual reality (VR) headset, etc.),vehicle (e.g., automobile, motorcycle, bicycle, etc.), Internet ofThings (IoT) device, etc.) used by a user to communicate over a wirelesscommunications network. A UE may be mobile or may (e.g., at certaintimes) be stationary, and may communicate with a radio access network(RAN). As used herein, the term “UE” may be referred to interchangeablyas an “access terminal” or “AT,” a “client device,” a “wireless device,”a “subscriber device,” a “subscriber terminal,” a “subscriber station,”a “user terminal” or UT, a “mobile device,” a “mobile terminal,” a“mobile station,” or variations thereof. Generally, UEs can communicatewith a core network via a RAN, and through the core network the UEs canbe connected with external networks such as the Internet and with otherUEs. Of course, other mechanisms of connecting to the core networkand/or the Internet are also possible for the UEs, such as over wiredaccess networks, wireless local area network (WLAN) networks (e.g.,based on IEEE 802.11, etc.) and so on.

A base station may operate according to one of several RATs incommunication with UEs depending on the network in which it is deployed,and may be alternatively referred to as an access point (AP), a networknode, a NodeB, an evolved NodeB (eNB), a next generation eNB (ng-eNB), aNew Radio (NR) Node B (also referred to as a gNB or gNodeB), etc. A basestation may be used primarily to support wireless access by UEs,including supporting data, voice, and/or signaling connections for thesupported UEs. In some systems a base station may provide purely edgenode signaling functions while in other systems it may provideadditional control and/or network management functions. A communicationlink through which UEs can send signals to a base station is called anuplink (UL) channel (e.g., a reverse traffic channel, a reverse controlchannel, an access channel, etc.). A communication link through whichthe base station can send signals to UEs is called a downlink (DL) orforward link channel (e.g., a paging channel, a control channel, abroadcast channel, a forward traffic channel, etc.). As used herein theterm traffic channel (TCH) can refer to either an UL/reverse orDL/forward traffic channel.

The term “base station” may refer to a single physicaltransmission-reception point (TRP) or to multiple physical TRPs that mayor may not be co-located. For example, where the term “base station”refers to a single physical TRP, the physical TRP may be an antenna ofthe base station corresponding to a cell (or several cell sectors) ofthe base station. Where the term “base station” refers to multipleco-located physical TRPs, the physical TRPs may be an array of antennas(e.g., as in a multiple-input multiple-output (MIMO) system or where thebase station employs beamforming) of the base station. Where the term“base station” refers to multiple non-co-located physical TRPs, thephysical TRPs may be a distributed antenna system (DAS) (a network ofspatially separated antennas connected to a common source via atransport medium) or a remote radio head (RRH) (a remote base stationconnected to a serving base station). Alternatively, the non-co-locatedphysical TRPs may be the serving base station receiving the measurementreport from the UE and a neighbor base station whose reference RFsignals the UE is measuring. Because a TRP is the point from which abase station transmits and receives wireless signals, as used herein,references to transmission from or reception at a base station are to beunderstood as referring to a particular TRP of the base station.

In some implementations that support positioning of UEs, a base stationmay not support wireless access by UEs (e.g., may not support data,voice, and/or signaling connections for UEs), but may instead transmitreference signals to UEs to be measured by the UEs, and/or may receiveand measure signals transmitted by the UEs. Such a base station may bereferred to as a positioning beacon (e.g., when transmitting signals toUEs) and/or as a location measurement unit (e.g., when receiving andmeasuring signals from UEs).

An “RF signal” comprises an electromagnetic wave of a given frequencythat transports information through the space between a transmitter anda receiver. As used herein, a transmitter may transmit a single “RFsignal” or multiple “RF signals” to a receiver. However, the receivermay receive multiple “RF signals” corresponding to each transmitted RFsignal due to the propagation characteristics of RF signals throughmultipath channels. The same transmitted RF signal on different pathsbetween the transmitter and receiver may be referred to as a “multipath”RF signal.

According to various aspects, FIG. 1 illustrates an example wirelesscommunications system 100. The wireless communications system 100 (whichmay also be referred to as a wireless wide area network (WWAN)) mayinclude various base stations 102 and various UEs 104. The base stations102 may include macro cell base stations (high power cellular basestations) and/or small cell base stations (low power cellular basestations). In an aspect, the macro cell base station may include eNBsand/or ng-eNBs where the wireless communications system 100 correspondsto an LTE network, or gNBs where the wireless communications system 100corresponds to a NR network, or a combination of both, and the smallcell base stations may include femtocells, picocells, microcells, etc.

The base stations 102 may collectively form a RAN and interface with acore network 170 (e.g., an evolved packet core (EPC) or a 5G core (5GC))through backhaul links 122, and through the core network 170 to one ormore location servers 172 (which may be part of core network 170 or maybe external to core network 170). In addition to other functions, thebase stations 102 may perform functions that relate to one or more oftransferring user data, radio channel ciphering and deciphering,integrity protection, header compression, mobility control functions(e.g., handover, dual connectivity), inter-cell interferencecoordination, connection setup and release, load balancing, distributionfor non-access stratum (NAS) messages, NAS node selection,synchronization, RAN sharing, multimedia broadcast multicast service(MBMS), subscriber and equipment trace, RAN information management(RIM), paging, positioning, and delivery of warning messages. The basestations 102 may communicate with each other directly or indirectly(e.g., through the EPC/5GC) over backhaul links 134, which may be wiredor wireless.

The base stations 102 may wirelessly communicate with the UEs 104. Eachof the base stations 102 may provide communication coverage for arespective geographic coverage area 110. In an aspect, one or more cellsmay be supported by a base station 102 in each coverage area 110. A“cell” is a logical communication entity used for communication with abase station (e.g., over some frequency resource, referred to as acarrier frequency, component carrier, carrier, band, or the like), andmay be associated with an identifier (e.g., a physical cell identifier(PCI), a virtual cell identifier (VCI), a cell global identifier (CGI))for distinguishing cells operating via the same or a different carrierfrequency. In some cases, different cells may be configured according todifferent protocol types (e.g., machine-type communication (MTC),narrowband IoT (NB-IoT), enhanced mobile broadband (eMBB), or others)that may provide access for different types of UEs. Because a cell issupported by a specific base station, the term “cell” may refer toeither or both of the logical communication entity and the base stationthat supports it, depending on the context. In some cases, the term“cell” may also refer to a geographic coverage area of a base station(e.g., a sector), insofar as a carrier frequency can be detected andused for communication within some portion of geographic coverage areas110.

While neighboring macro cell base station 102 geographic coverage areas110 may partially overlap (e.g., in a handover region), some of thegeographic coverage areas 110 may be substantially overlapped by alarger geographic coverage area 110. For example, a small cell basestation 102′ may have a coverage area 110′ that substantially overlapswith the coverage area 110 of one or more macro cell base stations 102.A network that includes both small cell and macro cell base stations maybe known as a heterogeneous network. A heterogeneous network may alsoinclude home eNBs (HeNBs), which may provide service to a restrictedgroup known as a closed subscriber group (CSG).

The communication links 120 between the base stations 102 and the UEs104 may include UL (also referred to as reverse link) transmissions froma UE 104 to a base station 102 and/or downlink (DL) (also referred to asforward link) transmissions from a base station 102 to a UE 104. Thecommunication links 120 may use MIMO antenna technology, includingspatial multiplexing, beamforming, and/or transmit diversity. Thecommunication links 120 may be through one or more carrier frequencies.Allocation of carriers may be asymmetric with respect to DL and UL(e.g., more or less carriers may be allocated for DL than for UL).

The wireless communications system 100 may further include a wirelesslocal area network (WLAN) access point (AP) 150 in communication withWLAN stations (STAs) 152 via communication links 154 in an unlicensedfrequency spectrum (e.g., 5 GHz). When communicating in an unlicensedfrequency spectrum, the WLAN STAs 152 and/or the WLAN AP 150 may performa clear channel assessment (CCA) or listen before talk (LBT) procedureprior to communicating in order to determine whether the channel isavailable.

The small cell base station 102′ may operate in a licensed and/or anunlicensed frequency spectrum. When operating in an unlicensed frequencyspectrum, the small cell base station 102′ may employ LTE or NRtechnology and use the same 5 GHz unlicensed frequency spectrum as usedby the WLAN AP 150. The small cell base station 102′, employing LTE/5Gin an unlicensed frequency spectrum, may boost coverage to and/orincrease capacity of the access network. NR in unlicensed spectrum maybe referred to as NR-U. LTE in an unlicensed spectrum may be referred toas LTE-U, licensed assisted access (LAA), or MulteFire.

The wireless communications system 100 may further include a millimeterwave (mmW) base station 180 that may operate in mmW frequencies and/ornear mmW frequencies in communication with a UE 182. Extremely highfrequency (EHF) is part of the RF in the electromagnetic spectrum. EHFhas a range of 30 GHz to 300 GHz and a wavelength between 1 millimeterand 10 millimeters. Radio waves in this band may be referred to as amillimeter wave. Near mmW may extend down to a frequency of 3 GHz with awavelength of 100 millimeters. The super high frequency (SHF) bandextends between 3 GHz and 30 GHz, also referred to as centimeter wave.Communications using the mmW/near mmW radio frequency band have highpath loss and a relatively short range. The mmW base station 180 and theUE 182 may utilize beamforming (transmit and/or receive) over a mmWcommunication link 184 to compensate for the extremely high path lossand short range. Further, it will be appreciated that in alternativeconfigurations, one or more base stations 102 may also transmit usingmmW or near mmW and beamforming. Accordingly, it will be appreciatedthat the foregoing illustrations are merely examples and should not beconstrued to limit the various aspects disclosed herein.

Transmit beamforming is a technique for focusing an RF signal in aspecific direction. Traditionally, when a network node (e.g., a basestation) broadcasts an RF signal, it broadcasts the signal in alldirections (omni-directionally). With transmit beamforming, the networknode determines where a given target device (e.g., a UE) is located(relative to the transmitting network node) and projects a strongerdownlink RF signal in that specific direction, thereby providing afaster (in terms of data rate) and stronger RF signal for the receivingdevice(s). To change the directionality of the RF signal whentransmitting, a network node can control the phase and relativeamplitude of the RF signal at each of the one or more transmitters thatare broadcasting the RF signal. For example, a network node may use anarray of antennas (referred to as a “phased array” or an “antennaarray”) that creates a beam of RF waves that can be “steered” to pointin different directions, without actually moving the antennas.Specifically, the RF current from the transmitter is fed to theindividual antennas with the correct phase relationship so that theradio waves from the separate antennas add together to increase theradiation in a desired direction, while cancelling to suppress radiationin undesired directions.

Transmit beams may be quasi-co-located, meaning that they appear to thereceiver (e.g., a UE) as having the same parameters, regardless ofwhether or not the transmitting antennas of the network node themselvesare physically co-located. In NR, there are four types ofquasi-co-location (QCL) relations. Specifically, a QCL relation of agiven type means that certain parameters about a target reference RFsignal on a target beam can be derived from information about a sourcereference RF signal on a source beam. If the source reference RF signalis QCL Type A, the receiver can use the source reference RF signal toestimate the Doppler shift, Doppler spread, average delay, and delayspread of a target reference RF signal transmitted on the same channel.If the source reference RF signal is QCL Type B, the receiver can usethe source reference RF signal to estimate the Doppler shift and Dopplerspread of a target reference RF signal transmitted on the same channel.If the source reference RF signal is QCL Type C, the receiver can usethe source reference RF signal to estimate the Doppler shift and averagedelay of a target reference RF signal transmitted on the same channel.If the source reference RF signal is QCL Type D, the receiver can usethe source reference RF signal to estimate the spatial receive parameterof a target reference RF signal transmitted on the same channel.

In receive beamforming, the receiver uses a receive beam to amplify RFsignals detected on a given channel. For example, the receiver canincrease the gain setting and/or adjust the phase setting of an array ofantennas in a particular direction to amplify (e.g., to increase thegain level of) the RF signals received from that direction. Thus, when areceiver is said to beamform in a certain direction, it means the beamgain in that direction is high relative to the beam gain along otherdirections, or the beam gain in that direction is the highest comparedto the beam gain in that direction of all other receive beams availableto the receiver. This results in a stronger received signal strength(e.g., reference signal received power (RSRP), reference signal receivedquality (RSRQ), signal-to-interference-plus-noise ratio (SINR), etc.) ofthe RF signals received from that direction.

Receive beams may be spatially related. A spatial relation means thatparameters for a transmit beam for a second reference signal can bederived from information about a receive beam for a first referencesignal. For example, a UE may use a particular receive beam to receiveone or more reference downlink reference signals (e.g., positioningreference signals (PRS), tracking reference signals (TRS), phasetracking reference signal (PTRS), cell-specific reference signals (CRS),channel state information reference signals (CSI-RS), primarysynchronization signals (PSS), secondary synchronization signals (SSS),synchronization signal blocks (SSBs), etc.) from a base station. The UEcan then form a transmit beam for sending one or more uplink referencesignals (e.g., uplink positioning reference signals (UL-PRS), soundingreference signal (SRS), demodulation reference signals (DMRS), PTRS,etc.) to that base station based on the parameters of the receive beam.

Note that a “downlink” beam may be either a transmit beam or a receivebeam, depending on the entity forming it. For example, if a base stationis forming the downlink beam to transmit a reference signal to a UE, thedownlink beam is a transmit beam. If the UE is forming the downlinkbeam, however, it is a receive beam to receive the downlink referencesignal. Similarly, an “uplink” beam may be either a transmit beam or areceive beam, depending on the entity forming it. For example, if a basestation is forming the uplink beam, it is an uplink receive beam, and ifa UE is forming the uplink beam, it is an uplink transmit beam.

In 5G, the frequency spectrum in which wireless nodes (e.g., basestations 102/180, UEs 104/182) operate is divided into multiplefrequency ranges, FR1 (from 450 to 6000 MHz), FR2 (from 24250 to 52600MHz), FR3 (above 52600 MHz), and FR4 (between FR1 and FR2). In amulti-carrier system, such as 5G, one of the carrier frequencies isreferred to as the “primary carrier” or “anchor carrier” or “primaryserving cell” or “PCell,” and the remaining carrier frequencies arereferred to as “secondary carriers” or “secondary serving cells” or“SCells.” In carrier aggregation, the anchor carrier is the carrieroperating on the primary frequency (e.g., FR1) utilized by a UE 104/182and the cell in which the UE 104/182 either performs the initial radioresource control (RRC) connection establishment procedure or initiatesthe RRC connection re-establishment procedure. The primary carriercarries all common and UE-specific control channels, and may be acarrier in a licensed frequency (however, this is not always the case).A secondary carrier is a carrier operating on a second frequency (e.g.,FR2) that may be configured once the RRC connection is establishedbetween the UE 104 and the anchor carrier and that may be used toprovide additional radio resources. In some cases, the secondary carriermay be a carrier in an unlicensed frequency. The secondary carrier maycontain only necessary signaling information and signals, for example,those that are UE-specific may not be present in the secondary carrier,since both primary uplink and downlink carriers are typicallyUE-specific. This means that different UEs 104/182 in a cell may havedifferent downlink primary carriers. The same is true for the uplinkprimary carriers. The network is able to change the primary carrier ofany UE 104/182 at any time. This is done, for example, to balance theload on different carriers. Because a “serving cell” (whether a PCell oran SCell) corresponds to a carrier frequency/component carrier overwhich some base station is communicating, the term “cell,” “servingcell,” “component carrier,” “carrier frequency,” and the like can beused interchangeably.

For example, still referring to FIG. 1 , one of the frequencies utilizedby the macro cell base stations 102 may be an anchor carrier (or“PCell”) and other frequencies utilized by the macro cell base stations102 and/or the mmW base station 180 may be secondary carriers(“SCells”). The simultaneous transmission and/or reception of multiplecarriers enables the UE 104/182 to significantly increase its datatransmission and/or reception rates. For example, two 20 MHz aggregatedcarriers in a multi-carrier system would theoretically lead to atwo-fold increase in data rate (i.e., 40 MHz), compared to that attainedby a single 20 MHz carrier.

The wireless communications system 100 may further include a UE 164 thatmay communicate with a macro cell base station 102 over a communicationlink 120 and/or the mmW base station 180 over a mmW communication link184. For example, the macro cell base station 102 may support a PCelland one or more SCells for the UE 164 and the mmW base station 180 maysupport one or more SCells for the UE 164.

The wireless communications system 100 may further include one or moreUEs, such as UE 190, that connects indirectly to one or morecommunication networks via one or more device-to-device (D2D)peer-to-peer (P2P) links (referred to as “sidelinks”). In the example ofFIG. 1 , UE 190 has a D2D P2P link 192 with one of the UEs 104 connectedto one of the base stations 102 (e.g., through which UE 190 mayindirectly obtain cellular connectivity) and a D2D P2P link 194 withWLAN STA 152 connected to the WLAN AP 150 (through which UE 190 mayindirectly obtain WLAN-based Internet connectivity). In an example, theD2D P2P links 192 and 194 may be supported with any well-known D2D RAT,such as LTE Direct (LTE-D), WiFi Direct (WiFi-D), Bluetooth®, and so on.

According to various aspects, FIG. 2A illustrates an example wirelessnetwork structure 200. For example, a 5GC 210 (also referred to as aNext Generation Core (NGC)) can be viewed functionally as control planefunctions 214 (e.g., UE registration, authentication, network access,gateway selection, etc.) and user plane functions 212, (e.g., UE gatewayfunction, access to data networks, IP routing, etc.) which operatecooperatively to form the core network. User plane interface (NG-U) 213and control plane interface (NG-C) 215 connect the gNB 222 to the 5GC210 and specifically to the control plane functions 214 and user planefunctions 212. In an additional configuration, an ng-eNB 224 may also beconnected to the 5GC 210 via NG-C 215 to the control plane functions 214and NG-U 213 to user plane functions 212. Further, ng-eNB 224 maydirectly communicate with gNB 222 via a backhaul connection 223. In someconfigurations, the New RAN 220 may only have one or more gNBs 222,while other configurations include one or more of both ng-eNBs 224 andgNBs 222. Either gNB 222 or ng-eNB 224 may communicate with UEs 204(e.g., any of the UEs depicted in FIG. 1 ). Another optional aspect mayinclude location server 230, which may be in communication with the 5GC210 to provide location assistance for UEs 204. The location server 230can be implemented as a plurality of separate servers (e.g., physicallyseparate servers, different software modules on a single server,different software modules spread across multiple physical servers,etc.), or alternately may each correspond to a single server. Thelocation server 230 can be configured to support one or more locationservices for UEs 204 that can connect to the location server 230 via thecore network, 5GC 210, and/or via the Internet (not illustrated).Further, the location server 230 may be integrated into a component ofthe core network, or alternatively may be external to the core network.

According to various aspects, FIG. 2B illustrates another examplewireless network structure 250. For example, a 5GC 260 can be viewedfunctionally as control plane functions, provided by an access andmobility management function (AMF) 264, and user plane functions,provided by a user plane function (UPF) 262, which operate cooperativelyto form the core network (i.e., 5GC 260). User plane interface 263 andcontrol plane interface 265 connect the ng-eNB 224 to the 5GC 260 andspecifically to UPF 262 and AMF 264, respectively. In an additionalconfiguration, a gNB 222 may also be connected to the 5GC 260 viacontrol plane interface 265 to AMF 264 and user plane interface 263 toUPF 262. Further, ng-eNB 224 may directly communicate with gNB 222 viathe backhaul connection 223, with or without gNB direct connectivity tothe 5GC 260. In some configurations, the New RAN 220 may only have oneor more gNBs 222, while other configurations include one or more of bothng-eNBs 224 and gNBs 222. Either gNB 222 or ng-eNB 224 may communicatewith UEs 204 (e.g., any of the UEs depicted in FIG. 1 ). The basestations of the New RAN 220 communicate with the AMF 264 over the N2interface and with the UPF 262 over the N3 interface.

The functions of the AMF 264 include registration management, connectionmanagement, reachability management, mobility management, lawfulinterception, transport for session management (SM) messages between theUE 204 and a session management function (SMF) 266, transparent proxyservices for routing SM messages, access authentication and accessauthorization, transport for short message service (SMS) messagesbetween the UE 204 and the short message service function (SMSF) (notshown), and security anchor functionality (SEAF). The AMF 264 alsointeracts with an authentication server function (AUSF) (not shown) andthe UE 204, and receives the intermediate key that was established as aresult of the UE 204 authentication process. In the case ofauthentication based on a UMTS (universal mobile telecommunicationssystem) subscriber identity module (USIM), the AMF 264 retrieves thesecurity material from the AUSF. The functions of the AMF 264 alsoinclude security context management (SCM). The SCM receives a key fromthe SEAF that it uses to derive access-network specific keys. Thefunctionality of the AMF 264 also includes location services managementfor regulatory services, transport for location services messagesbetween the UE 204 and a location management function (LMF) 270 (whichacts as a location server 230), transport for location services messagesbetween the New RAN 220 and the LMF 270, evolved packet system (EPS)bearer identifier allocation for interworking with the EPS, and UE 204mobility event notification. In addition, the AMF 164 also supportsfunctionalities for non-3GPP access networks.

Functions of the UPF 262 include acting as an anchor point forintra-/inter-RAT mobility (when applicable), acting as an externalprotocol data unit (PDU) session point of interconnect to a data network(not shown), providing packet routing and forwarding, packet inspection,user plane policy rule enforcement (e.g., gating, redirection, trafficsteering), lawful interception (user plane collection), traffic usagereporting, quality of service (QoS) handling for the user plane (e.g.,UL/DL rate enforcement, reflective QoS marking in the DL), UL trafficverification (service data flow (SDF) to QoS flow mapping), transportlevel packet marking in the UL and DL, DL packet buffering and DL datanotification triggering, and sending and forwarding of one or more “endmarkers” to the source RAN node. The UPF 262 may also support transferof location services messages over a user plane between the UE 204 and alocation server, such as a secure user plane location (SUPL) locationplatform (SLP) 272.

The functions of the SMF 266 include session management, UE Internetprotocol (IP) address allocation and management, selection and controlof user plane functions, configuration of traffic steering at the UPF262 to route traffic to the proper destination, control of part ofpolicy enforcement and QoS, and downlink data notification. Theinterface over which the SMF 266 communicates with the AMF 264 isreferred to as the N11 interface.

Another optional aspect may include an LMF 270, which may be incommunication with the 5GC 260 to provide location assistance for UEs204. The LMF 270 can be implemented as a plurality of separate servers(e.g., physically separate servers, different software modules on asingle server, different software modules spread across multiplephysical servers, etc.), or alternately may each correspond to a singleserver. The LMF 270 can be configured to support one or more locationservices for UEs 204 that can connect to the LMF 270 via the corenetwork, 5GC 260, and/or via the Internet (not illustrated). The SLP 272may support similar functions to the LMF 270, but whereas the LMF 270may communicate with the AMF 264, New RAN 220, and UEs 204 over acontrol plane (e.g., using interfaces and protocols intended to conveysignaling messages and not voice or data), the SLP 270 may communicatewith UEs 204 and external clients (not shown in FIG. 2B) over a userplane (e.g., using protocols intended to carry voice and/or data likethe transmission control protocol (TCP) and/or IP).

FIGS. 3A, 3B, and 3C illustrate several example components (representedby corresponding blocks) that may be incorporated into a UE 302 (whichmay correspond to any of the UEs described herein), a base station 304(which may correspond to any of the base stations described herein), anda network entity 306 (which may correspond to or embody any of thenetwork functions described herein, including the location server 230and the LMF 270) to support the file transmission operations as taughtherein. It will be appreciated that these components may be implementedin different types of apparatuses in different implementations (e.g., inan ASIC, in a system-on-chip (SoC), etc.). The illustrated componentsmay also be incorporated into other apparatuses in a communicationsystem. For example, other apparatuses in a system may includecomponents similar to those described to provide similar functionality.Also, a given apparatus may contain one or more of the components. Forexample, an apparatus may include multiple transceiver components thatenable the apparatus to operate on multiple carriers and/or communicatevia different technologies.

The UE 302 and the base station 304 each include wireless wide areanetwork (WWAN) transceiver 310 and 350, respectively, providing meansfor communicating (e.g., means for transmitting, means for receiving,means for measuring, means for tuning, means for refraining fromtransmitting, etc.) via one or more wireless communication networks (notshown), such as an NR network, an LTE network, a GSM network, and/or thelike. The WWAN transceivers 310 and 350 may be connected to one or moreantennas 316 and 356, respectively, for communicating with other networknodes, such as other UEs, access points, base stations (e.g., eNBs,gNBs), etc., via at least one designated RAT (e.g., NR, LTE, GSM, etc.)over a wireless communication medium of interest (e.g., some set oftime/frequency resources in a particular frequency spectrum). The WWANtransceivers 310 and 350 may be variously configured for transmittingand encoding signals 318 and 358 (e.g., messages, indications,information, and so on), respectively, and, conversely, for receivingand decoding signals 318 and 358 (e.g., messages, indications,information, pilots, and so on), respectively, in accordance with thedesignated RAT. Specifically, the WWAN transceivers 310 and 350 includeone or more transmitters 314 and 354, respectively, for transmitting andencoding signals 318 and 358, respectively, and one or more receivers312 and 352, respectively, for receiving and decoding signals 318 and358, respectively.

The UE 302 and the base station 304 also include, at least in somecases, wireless local area network (WLAN) transceivers 320 and 360,respectively. The WLAN transceivers 320 and 360 may be connected to oneor more antennas 326 and 366, respectively, and provide means forcommunicating (e.g., means for transmitting, means for receiving, meansfor measuring, means for tuning, means for refraining from transmitting,etc.) with other network nodes, such as other UEs, access points, basestations, etc., via at least one designated RAT (e.g., WiFi, LTE-D,Bluetooth®, etc.) over a wireless communication medium of interest. TheWLAN transceivers 320 and 360 may be variously configured fortransmitting and encoding signals 328 and 368 (e.g., messages,indications, information, and so on), respectively, and, conversely, forreceiving and decoding signals 328 and 368 (e.g., messages, indications,information, pilots, and so on), respectively, in accordance with thedesignated RAT. Specifically, the WLAN transceivers 320 and 360 includeone or more transmitters 324 and 364, respectively, for transmitting andencoding signals 328 and 368, respectively, and one or more receivers322 and 362, respectively, for receiving and decoding signals 328 and368, respectively.

Transceiver circuitry including at least one transmitter and at leastone receiver may comprise an integrated device (e.g., embodied as atransmitter circuit and a receiver circuit of a single communicationdevice) in some implementations, may comprise a separate transmitterdevice and a separate receiver device in some implementations, or may beembodied in other ways in other implementations. In an aspect, atransmitter may include or be coupled to a plurality of antennas (e.g.,antennas 316, 326, 356, 366), such as an antenna array, that permits therespective apparatus to perform transmit “beamforming,” as describedherein. Similarly, a receiver may include or be coupled to a pluralityof antennas (e.g., antennas 316, 326, 356, 366), such as an antennaarray, that permits the respective apparatus to perform receivebeamforming, as described herein. In an aspect, the transmitter andreceiver may share the same plurality of antennas (e.g., antennas 316,326, 356, 366), such that the respective apparatus can only receive ortransmit at a given time, not both at the same time. A wirelesscommunication device (e.g., one or both of the transceivers 310 and 320and/or 350 and 360) of the UE 302 and/or the base station 304 may alsocomprise a network listen module (NLM) or the like for performingvarious measurements.

The UE 302 and the base station 304 also include, at least in somecases, satellite positioning systems (SPS) receivers 330 and 370. TheSPS receivers 330 and 370 may be connected to one or more antennas 336and 376, respectively, and may provide means for receiving and/ormeasuring SPS signals 338 and 378, respectively, such as globalpositioning system (GPS) signals, global navigation satellite system(GLONASS) signals, Galileo signals, Beidou signals, Indian RegionalNavigation Satellite System (NAVIC), Quasi-Zenith Satellite System(QZSS), etc. The SPS receivers 330 and 370 may comprise any suitablehardware and/or software for receiving and processing SPS signals 338and 378, respectively. The SPS receivers 330 and 370 request informationand operations as appropriate from the other systems, and performscalculations necessary to determine positions of the UE 302 and the basestation 304 using measurements obtained by any suitable SPS algorithm.

The base station 304 and the network entity 306 each include at leastone network interfaces 380 and 390, respectively, providing means forcommunicating (e.g., means for transmitting, means for receiving, etc.)with other network entities. For example, the network interfaces 380 and390 (e.g., one or more network access ports) may be configured tocommunicate with one or more network entities via a wire-based orwireless backhaul connection. In some aspects, the network interfaces380 and 390 may be implemented as transceivers configured to supportwire-based or wireless signal communication. This communication mayinvolve, for example, sending and receiving messages, parameters, and/orother types of information.

The UE 302, the base station 304, and the network entity 306 alsoinclude other components that may be used in conjunction with theoperations as disclosed herein. The UE 302 includes processor circuitryimplementing a processing system 332 for providing functionalityrelating to, for example, wireless communication, and for providingother processing functionality. The base station 304 includes aprocessing system 384 for providing functionality relating to, forexample, wireless communication as disclosed herein, and for providingother processing functionality. The network entity 306 includes aprocessing system 394 for providing functionality relating to, forexample, wireless communication as disclosed herein, and for providingother processing functionality. The processing systems 332, 384, and 394may therefore provide means for processing, such as means fordetermining, means for calculating, means for receiving, means fortransmitting, means for indicating, etc. In an aspect, the processingsystems 332, 384, and 394 may include, for example, one or more generalpurpose processors, multi-core processors, ASICs, digital signalprocessors (DSPs), field programmable gate arrays (FPGA), or otherprogrammable logic devices or processing circuitry.

The UE 302, the base station 304, and the network entity 306 includememory circuitry implementing memory components 340, 386, and 396 (e.g.,each including a memory device), respectively, for maintaininginformation (e.g., information indicative of reserved resources,thresholds, parameters, and so on). The memory components 340, 386, and396 may therefore provide means for storing, means for retrieving, meansfor maintaining, etc. In some cases, the UE 302, the base station 304,and the network entity 306 may include positioning components 342, 388,and 398, respectively. The positioning components 342, 388, and 398 maybe hardware circuits that are part of or coupled to the processingsystems 332, 384, and 394, respectively, that, when executed, cause theUE 302, the base station 304, and the network entity 306 to perform thefunctionality described herein. In other aspects, the positioningcomponents 342, 388, and 398 may be external to the processing systems332, 384, and 394 (e.g., part of a modem processing system, integratedwith another processing system, etc.).

Alternatively, the positioning components 342, 388, and 398 may bememory modules stored in the memory components 340, 386, and 396,respectively, that, when executed by the processing systems 332, 384,and 394 (or a modem processing system, another processing system, etc.),cause the UE 302, the base station 304, and the network entity 306 toperform the functionality described herein. FIG. 3A illustrates possiblelocations of the positioning component 342, which may be part of theWWAN transceiver 310, the memory component 340, the processing system332, or any combination thereof, or may be a standalone component. FIG.3B illustrates possible locations of the positioning component 388,which may be part of the WWAN transceiver 350, the memory component 386,the processing system 384, or any combination thereof, or may be astandalone component. FIG. 3C illustrates possible locations of thepositioning component 398, which may be part of the network interface(s)390, the memory component 396, the processing system 394, or anycombination thereof, or may be a standalone component.

The UE 302 may include one or more sensors 344 coupled to the processingsystem 332 to provide means for sensing or detecting movement and/ororientation information that is independent of motion data derived fromsignals received by the WWAN transceiver 310, the WLAN transceiver 320,and/or the SPS receiver 330. By way of example, the sensor(s) 344 mayinclude an accelerometer (e.g., a micro-electrical mechanical systems(MEMS) device), a gyroscope, a geomagnetic sensor (e.g., a compass), analtimeter (e.g., a barometric pressure altimeter), and/or any other typeof movement detection sensor. Moreover, the sensor(s) 344 may include aplurality of different types of devices and combine their outputs inorder to provide motion information. For example, the sensor(s) 344 mayuse a combination of a multi-axis accelerometer and orientation sensorsto provide the ability to compute positions in 2D and/or 3D coordinatesystems.

In addition, the UE 302 includes a user interface 346 providing meansfor providing indications (e.g., audible and/or visual indications) to auser and/or for receiving user input (e.g., upon user actuation of asensing device such a keypad, a touch screen, a microphone, and so on).Although not shown, the base station 304 and the network entity 306 mayalso include user interfaces.

Referring to the processing system 384 in more detail, in the downlink,IP packets from the network entity 306 may be provided to the processingsystem 384. The processing system 384 may implement functionality for anRRC layer, a packet data convergence protocol (PDCP) layer, a radio linkcontrol (RLC) layer, and a medium access control (MAC) layer. Theprocessing system 384 may provide RRC layer functionality associatedwith broadcasting of system information (e.g., master information block(MIB), system information blocks (Ms)), RRC connection control (e.g.,RRC connection paging, RRC connection establishment, RRC connectionmodification, and RRC connection release), inter-RAT mobility, andmeasurement configuration for UE measurement reporting; PDCP layerfunctionality associated with header compression/decompression, security(ciphering, deciphering, integrity protection, integrity verification),and handover support functions; RLC layer functionality associated withthe transfer of upper layer PDUs, error correction through automaticrepeat request (ARQ), concatenation, segmentation, and reassembly of RLCservice data units (SDUs), re-segmentation of RLC data PDUs, andreordering of RLC data PDUs; and MAC layer functionality associated withmapping between logical channels and transport channels, schedulinginformation reporting, error correction, priority handling, and logicalchannel prioritization.

The transmitter 354 and the receiver 352 may implement Layer-1 (L1)functionality associated with various signal processing functions.Layer-1, which includes a physical (PHY) layer, may include errordetection on the transport channels, forward error correction (FEC)coding/decoding of the transport channels, interleaving, rate matching,mapping onto physical channels, modulation/demodulation of physicalchannels, and MIMO antenna processing. The transmitter 354 handlesmapping to signal constellations based on various modulation schemes(e.g., binary phase-shift keying (BPSK), quadrature phase-shift keying(QPSK), M-phase-shift keying (M-PSK), M-quadrature amplitude modulation(M-QAM)). The coded and modulated symbols may then be split intoparallel streams. Each stream may then be mapped to an orthogonalfrequency division multiplexing (OFDM) subcarrier, multiplexed with areference signal (e.g., pilot) in the time and/or frequency domain, andthen combined together using an inverse fast Fourier transform (IFFT) toproduce a physical channel carrying a time domain OFDM symbol stream.The OFDM symbol stream is spatially precoded to produce multiple spatialstreams. Channel estimates from a channel estimator may be used todetermine the coding and modulation scheme, as well as for spatialprocessing. The channel estimate may be derived from a reference signaland/or channel condition feedback transmitted by the UE 302. Eachspatial stream may then be provided to one or more different antennas356. The transmitter 354 may modulate an RF carrier with a respectivespatial stream for transmission.

At the UE 302, the receiver 312 receives a signal through its respectiveantenna(s) 316. The receiver 312 recovers information modulated onto anRF carrier and provides the information to the processing system 332.The transmitter 314 and the receiver 312 implement Layer-1 functionalityassociated with various signal processing functions. The receiver 312may perform spatial processing on the information to recover any spatialstreams destined for the UE 302. If multiple spatial streams aredestined for the UE 302, they may be combined by the receiver 312 into asingle OFDM symbol stream. The receiver 312 then converts the OFDMsymbol stream from the time-domain to the frequency domain using a fastFourier transform (FFT). The frequency domain signal comprises aseparate OFDM symbol stream for each subcarrier of the OFDM signal. Thesymbols on each subcarrier, and the reference signal, are recovered anddemodulated by determining the most likely signal constellation pointstransmitted by the base station 304. These soft decisions may be basedon channel estimates computed by a channel estimator. The soft decisionsare then decoded and de-interleaved to recover the data and controlsignals that were originally transmitted by the base station 304 on thephysical channel. The data and control signals are then provided to theprocessing system 332, which implements Layer-3 (L3) and Layer-2 (L2)functionality.

In the uplink, the processing system 332 provides demultiplexing betweentransport and logical channels, packet reassembly, deciphering, headerdecompression, and control signal processing to recover IP packets fromthe core network. The processing system 332 is also responsible forerror detection.

Similar to the functionality described in connection with the downlinktransmission by the base station 304, the processing system 332 providesRRC layer functionality associated with system information (e.g., MIB,SIBS) acquisition, RRC connections, and measurement reporting; PDCPlayer functionality associated with header compression/decompression,and security (ciphering, deciphering, integrity protection, integrityverification); RLC layer functionality associated with the transfer ofupper layer PDUs, error correction through ARQ, concatenation,segmentation, and reassembly of RLC SDUs, re-segmentation of RLC dataPDUs, and reordering of RLC data PDUs; and MAC layer functionalityassociated with mapping between logical channels and transport channels,multiplexing of MAC SDUs onto transport blocks (TBs), demultiplexing ofMAC SDUs from TBs, scheduling information reporting, error correctionthrough hybrid automatic repeat request (HARD), priority handling, andlogical channel prioritization.

Channel estimates derived by the channel estimator from a referencesignal or feedback transmitted by the base station 304 may be used bythe transmitter 314 to select the appropriate coding and modulationschemes, and to facilitate spatial processing. The spatial streamsgenerated by the transmitter 314 may be provided to different antenna(s)316. The transmitter 314 may modulate an RF carrier with a respectivespatial stream for transmission.

The uplink transmission is processed at the base station 304 in a mannersimilar to that described in connection with the receiver function atthe UE 302. The receiver 352 receives a signal through its respectiveantenna(s) 356. The receiver 352 recovers information modulated onto anRF carrier and provides the information to the processing system 384.

In the uplink, the processing system 384 provides demultiplexing betweentransport and logical channels, packet reassembly, deciphering, headerdecompression, control signal processing to recover IP packets from theUE 302. IP packets from the processing system 384 may be provided to thecore network. The processing system 384 is also responsible for errordetection.

For convenience, the UE 302, the base station 304, and/or the networkentity 306 are shown in FIGS. 3A-C as including various components thatmay be configured according to the various examples described herein. Itwill be appreciated, however, that the illustrated blocks may havedifferent functionality in different designs.

The various components of the UE 302, the base station 304, and thenetwork entity 306 may communicate with each other over data buses 334,382, and 392, respectively. The components of FIGS. 3A-C may beimplemented in various ways. In some implementations, the components ofFIGS. 3A-C may be implemented in one or more circuits such as, forexample, one or more processors and/or one or more ASICs (which mayinclude one or more processors). Here, each circuit may use and/orincorporate at least one memory component for storing information orexecutable code used by the circuit to provide this functionality. Forexample, some or all of the functionality represented by blocks 310 to346 may be implemented by processor and memory component(s) of the UE302 (e.g., by execution of appropriate code and/or by appropriateconfiguration of processor components). Similarly, some or all of thefunctionality represented by blocks 350 to 388 may be implemented byprocessor and memory component(s) of the base station 304 (e.g., byexecution of appropriate code and/or by appropriate configuration ofprocessor components). Also, some or all of the functionalityrepresented by blocks 390 to 398 may be implemented by processor andmemory component(s) of the network entity 306 (e.g., by execution ofappropriate code and/or by appropriate configuration of processorcomponents). For simplicity, various operations, acts, and/or functionsare described herein as being performed “by a UE,” “by a base station,”“by a positioning entity,” etc. However, as will be appreciated, suchoperations, acts, and/or functions may actually be performed by specificcomponents or combinations of components of the UE, base station,positioning entity, etc., such as the processing systems 332, 384, 394,the transceivers 310, 320, 350, and 360, the memory components 340, 386,and 396, the positioning components 342, 388, and 398, etc.

Various frame structures may be used to support downlink and uplinktransmissions between network nodes (e.g., base stations and UEs). FIG.4A is a diagram 400 illustrating an example of an uplink framestructure, according to aspects of the disclosure. FIG. 4B is a diagram430 illustrating an example of channels within an uplink framestructure, according to aspects of the disclosure. Other wirelesscommunications technologies may have different frame structures and/ordifferent channels.

LTE, and in some cases NR, utilizes OFDM on the downlink andsingle-carrier frequency division multiplexing (SC-FDM) on the uplink.Unlike LTE, however, NR has an option to use OFDM on the uplink as well.OFDM and SC-FDM partition the system bandwidth into multiple (K)orthogonal subcarriers, which are also commonly referred to as tones,bins, etc. Each subcarrier may be modulated with data. In general,modulation symbols are sent in the frequency domain with OFDM and in thetime domain with SC-FDM. The spacing between adjacent subcarriers may befixed, and the total number of subcarriers (K) may be dependent on thesystem bandwidth. For example, the spacing of the subcarriers may be 15kilohertz (kHz) and the minimum resource allocation (resource block) maybe 12 subcarriers (or 180 kHz). Consequently, the nominal FFT size maybe equal to 128, 256, 512, 1024, or 2048 for system bandwidth of 1.25,2.5, 5, 10, or 20 megahertz (MHz), respectively. The system bandwidthmay also be partitioned into subbands. For example, a subband may cover1.08 MHz (i.e., 6 resource blocks), and there may be 1, 2, 4, 8, or 16subbands for system bandwidth of 1.25, 2.5, 5, 10, or 20 MHz,respectively.

LTE supports a single numerology (subcarrier spacing, symbol length,etc.). In contrast, NR may support multiple numerologies (μ), forexample, subcarrier spacing of 15 kHz, 30 kHz, 60 kHz, 120 kHz, and 240kHz or greater may be available. Table 1 provided below lists somevarious parameters for different NR numerologies.

TABLE 1 Max. nominal Slot Symbol system BW SCS Symbols/ Slots/ Slots/Duration Duration (MHz) with μ (kHz) Sot Subframe Frame (ms) (μs) 4K FFTsize 0 15 14 1 10 1 66.7 50 1 30 14 2 20 0.5 33.3 100 2 60 14 4 40 0.2516.7 100 3 120 14 8 80 0.125 8.33 400 4 240 14 16 160 0.0625 4.17 800

In the example of FIGS. 4A and 4B, a numerology of 15 kHz is used. Thus,in the time domain, a 10 millisecond (ms) frame is divided into 10equally sized subframes of 1 ms each, and each subframe includes onetime slot. In FIGS. 4A and 4B, time is represented horizontally (on theX axis) with time increasing from left to right, while frequency isrepresented vertically (on the Y axis) with frequency increasing (ordecreasing) from bottom to top.

A resource grid may be used to represent time slots, each time slotincluding one or more time-concurrent resource blocks (RBs) (alsoreferred to as physical RBs (PRBs)) in the frequency domain. Theresource grid is further divided into multiple resource elements (REs).An RE may correspond to one symbol length in the time domain and onesubcarrier in the frequency domain. In the numerology of FIGS. 4A and4B, for a normal cyclic prefix, an RB may contain 12 consecutivesubcarriers in the frequency domain and seven consecutive symbols in thetime domain, for a total of 84 REs. For an extended cyclic prefix, an RBmay contain 12 consecutive subcarriers in the frequency domain and sixconsecutive symbols in the time domain, for a total of 72 REs. Thenumber of bits carried by each RE depends on the modulation scheme.

As illustrated in FIG. 4A, some of the REs (labeled “R”) carrydemodulation reference signals (DMRS) for channel estimation at thereceiver (e.g., a base station, another UE, etc.). A UE may additionallytransmit SRS in, for example, the last symbol of a slot. The SRS mayhave a comb structure, and a UE may transmit SRS on one of the combs. Inthe example of FIG. 4A, the illustrated SRS is comb-2 over one symbol.The SRS may be used by a base station to obtain the channel stateinformation (CSI) for each UE. CSI describes how an RF signal propagatesfrom the UE to the base station and represents the combined effect ofscattering, fading, and power decay with distance. The system uses theSRS for resource scheduling, link adaptation, massive MIMO, beammanagement, etc.

Currently, an SRS resource may span 1, 2, 4, 8, or 12 consecutivesymbols within a slot with a comb size of comb-2, comb-4, or comb-8. Thefollowing table shows the frequency offsets from symbol to symbol forthe SRS comb patterns that are currently supported.

TABLE 2 1 2 4 8 12 Comb Symbol Symbols Symbols Symbols Symbols 2 {0} {0,1} {0, 1, 0, 1} NA NA 4 NA {0, 2} {0, 2, 1, 3} {0, 2, 1, 3, {0, 2, 1, 3,0, 2, 0, 2, 1, 3} 1, 3, 0, 2, 1, 3} 8 NA NA {0, 4, 2, 6} {0, 4, 2, 6,{0, 4, 2, 6, 1, 5, 1, 5, 3, 7} 3, 7, 0, 4, 2, 6}

A collection of resource elements that are used for transmission of SRSis referred to as an “SRS resource,” and may be identified by theparameter SRS-ResourceId. The collection of resource elements can spanmultiple PRBs in the frequency domain and N (e.g., one or more)consecutive symbol(s) within a slot in the time domain. In a given OFDMsymbol, an SRS resource occupies consecutive PRBs. An “SRS resource set”is a set of SRS resources used for the transmission of SRS signals, andis identified by an SRS resource set ID (SRS-ResourceSetId).

Generally, a UE transmits SRS to enable the receiving base station(either the serving base station or a neighboring base station) tomeasure the channel quality between the UE and the base station.However, SRS also can be used as uplink positioning reference signalsfor uplink positioning procedures, such as uplink time-difference ofarrival (UL-TDOA), multi-round-trip-time (multi-RTT), downlinkangle-of-arrival (DL-AoA), etc.

Several enhancements over the previous definition of SRS have beenproposed for SRS-for-positioning (also referred to as “UL-PRS”), such asa new staggered pattern within an SRS resource (except forsingle-symbol/comb-2), a new comb type for SRS, new sequences for SRS, ahigher number of SRS resource sets per component carrier, and a highernumber of SRS resources per component carrier. In addition, theparameters SpatialRelationInfo and PathLossReference are to beconfigured based on a downlink reference signal or SSB from aneighboring TRP. Further still, one SRS resource may be transmittedoutside the active BWP, and one SRS resource may span across multiplecomponent carriers. Also, SRS may be configured in RRC connected stateand only transmitted within an active BWP. Further, there may be nofrequency hopping, no repetition factor, a single antenna port, and newlengths for SRS (e.g., 8 and 12 symbols). There also may be open-looppower control and not closed-loop power control, and comb-8 (i.e., anSRS transmitted every eighth subcarrier in the same symbol) may be used.Lastly, the UE may transmit through the same transmit beam from multipleSRS resources for UL-AoA. All of these are features that are additionalto the current SRS framework, which is configured through RRC higherlayer signaling (and potentially triggered or activated through MACcontrol element (CE) or DCI).

FIG. 4B illustrates an example of various channels within an uplink slotof a frame, according to aspects of the disclosure. A random-accesschannel (RACH), also referred to as a physical random-access channel(PRACH), may be within one or more slots within a frame based on thePRACH configuration. The PRACH may include six consecutive RB pairswithin a slot. The PRACH allows the UE to perform initial system accessand achieve uplink synchronization. A physical uplink control channel(PUCCH) may be located on edges of the uplink system bandwidth. ThePUCCH carries uplink control information (UCI), such as schedulingrequests, CSI reports, a channel quality indicator (CQI), a precodingmatrix indicator (PMI), a rank indicator (RI), and HARQ ACK/NACKfeedback. The physical uplink shared channel (PUSCH) carries data, andmay additionally be used to carry a buffer status report (BSR), a powerheadroom report (PHR), and/or UCI.

Note that the terms “positioning reference signal” and “PRS” maysometimes refer to specific reference signals that are used forpositioning in LTE and NR systems. However, as used herein, unlessotherwise indicated, the terms “positioning reference signal” and “PRS”refer to any type of reference signal that can be used for positioning,such as but not limited to, PRS as defined in LTE and 5G, TRS, PTRS,CRS, CSI-RS, DMRS, PSS, SSS, SSB, SRS, UL-PRS, etc. In addition, theterms “positioning reference signal” and “PRS” refer to downlink oruplink positioning reference signals, unless otherwise indicated. Adownlink positioning reference signal may be referred to as a “DL-PRS,”and an uplink positioning reference signal (e.g., anSRS-for-positioning, PTRS) may be referred to as an “UL-PRS.” Inaddition, for signals that may be transmitted in both the uplink anddownlink (e.g., DMRS, PTRS), the signals may be prepended with “UL” or“DL” to distinguish the direction. For example, “UL-DMRS” may bedifferentiated from “DL-DMRS.”

FIG. 5 illustrates an example four-step random access procedure 500,according to aspects of the disclosure. The four-step random accessprocedure 500 is performed between a UE 504 and a base station 502(illustrated as a gNB), which may correspond to any of the UEs and basestations, respectively, described herein.

There are various situations in which a UE may perform the four-steprandom access procedure 500 (also referred to as a “RACH procedure,” a“PRACH procedure,” and the like). For example, a UE may perform thefour-step random access procedure 500 when acquiring initial networkaccess after coming out of the RRC idle state, when performing an RRCconnection re-establishment procedure, during a handover, when downlinkor uplink data arrives and the UE is in an RRC connected state but itsuplink synchronization status is “not-synchronized,” when transitioningout of the RRC INACTIVE state, when establishing time alignment for theaddition of an SCell, when requesting other synchronization information,or when performing beam failure recovery.

Before performing the four-step random access procedure 500, the UE 504first reads one or more SSBs broadcasted by the base station 502 withwhich the UE 504 is performing the four-step random access procedure500. In NR, each beam transmitted by a base station (e.g., base station502) is associated with a different SSB, and a UE (e.g., UE 504) selectsa certain beam to use to communicate with the base station 502. Based onthe SSB of the selected beam, the UE 504 can then read the SIB type 1(SIB1), which carries cell access related information and supplies theUE 504 with the scheduling of other system information blocks,transmitted on the selected beam.

When the UE sends the very first message of the four-step random accessprocedure 500 to the base station 502, it sends a specific patterncalled a preamble (also referred to as a RACH preamble, a PRACHpreamble, or a sequence). The RACH preamble differentiates requests fromdifferent UEs 504. However, if two UEs 504 use the same RACH preamble atthe same time, then there can be a collision. There are a total of 64such patterns available to a UE 504, and, for contention-based randomaccess, the UE 504 chooses one of them randomly. For contention-freerandom access, however, the network instructs the UE 504 about which oneto use.

At 510, the UE 504 selects one of 64 RACH preambles to send to the basestation 502 as a RACH request. This message is referred to as “Message1” or “Msg1” in a four-step RACH procedure. Based on the synchronizationinformation from the base station 502 (i.e., the SIB1), the UE 504selects a RACH preamble and sends it at the RACH occasion (RO)corresponding to the selected SSB/beam. More specifically, in order forthe base station 502 to determine which beam the UE 504 has selected, aspecific mapping is defined between an SSB and an RO (which occur every10, 20, 40, 80, or 160 ms). By detecting at which RO the UE 504 sent thepreamble, the base station 502 can determine which SSB/beam the UE 504selected.

Note that an RO is a time-frequency transmission opportunity fortransmitting a RACH preamble, and a RACH preamble index (i.e., a valuefrom 0 to 63 for the 64 possible preambles) enables the UE 504 togenerate the type of RACH preamble expected at the base station 502. TheRO and RACH preamble index may be configured to the UE 504 by the basestation 502 in a SIB. A RACH resource is an RO in which one RACHpreamble index is transmitted. As such, the terms “RO” (or “RACHoccasion”) and “RACH resource” may be used interchangeably, depending onthe context.

Due to reciprocity, the UE 504 may use the uplink transmit beamcorresponding to the best downlink receive beam determined duringsynchronization (i.e., the best receive beam to receive the selecteddownlink beam from the base station 502). That is, the UE 504 uses theparameters of the downlink receive beam used to receive the beam fromthe base station 502 to determine the parameters of the uplink transmitbeam. If reciprocity is available at the base station 502, the UE 504can transmit the preamble over one beam. Otherwise, the UE 504 repeatstransmission of the same preamble on all of its uplink transmit beams.

The UE 504 also needs to provide its identity to the network (via basestation 502) so that the network can address it in the next step. Thisidentity is called the random access radio network temporary identity(RA-RNTI) and is determined from the time slot in which the RACHpreamble is sent. If the UE 504 does not receive any response from thebase station 502 within some period of time, it increases itstransmission power in a fixed step and sends the RACH preamble/Msg1again.

At 520, the base station 502 sends a random access response (RAR),referred to as a “Message 2” or “Msg2” in a four-step RACH procedure, tothe UE 504 on the selected beam. The RAR is sent on a physical downlinkshared channel (PDSCH) and is addressed to the RA-RNTI calculated fromthe time slot (i.e., RO) in which the preamble was sent. The RAR carriesthe following information: a cell-radio network temporary identifier(C-RNTI), a timing advance (TA) value, and an uplink grant resource. Thebase station 502 assigns the C-RNTI to the UE 504 to enable furthercommunication with the UE 504. The TA value specifies how much the UE504 should change its timing to compensate for the round-trip delaybetween the UE 504 and the base station 502. The uplink grant resourceindicates the initial resources the UE 504 can use on the PUSCH. Afterthis step, the UE 504 and the base station 502 establish coarse beamalignment that can be utilized in the subsequent steps.

At 530, using the allocated PUSCH, the UE 504 sends an RRC connectionrequest message, referred to as a “Message 3” or “Msg3,” to the basestation 502. Because the UE 504 sends the Msg3 over the resourcesscheduled by the base station 502, the base station 502 therefore knowswhere to detect the Msg3 and which uplink receive beam should be used.Note that the Msg3 PUSCH can be sent on the same or different uplinktransmit beam than the Msg1.

The UE 504 identifies itself in the Msg3 by the C-RNTI assigned in theprevious step. The message contains the UE's 504 identity and connectionestablishment cause. The UE's 504 identity is either a temporary mobilesubscriber identity (TMSI) or a random value. A TMSI is used if the UE504 has previously connected to the same network. The UE 504 isidentified in the core network by the TMSI. A random value is used ifthe UE 504 is connecting to the network for the very first time. Thereason for the random value or TMSI is that the C-RNTI may have beenassigned to more than one UE in the previous step, due to multiplerequests arriving at the same time. The connection establishment causeindicates the reason why the UE 504 needs to connect to the network, andwill be described further below.

At 540, if the Msg3 was successfully received, the base station 502responds with a contention resolution message, referred to as a “Message4” or “Msg4.” This message is addressed to the TMSI or random value(from the Msg3) but contains a new C-RNTI that will be used for furthercommunication. Specifically, the base station 502 sends the Msg4 in thePDSCH using the downlink transmit beam determined in the previous step.

The four-step random access procedure 500 described above is acontention-based random access procedure. In contention-based randomaccess, any UE 504 connecting to the same cell or TRP sends the samerequest, in which case there is a possibility of collision among therequests from the various UEs 504. In contention-free random access, thenetwork can instruct a UE 504 to use some unique identity to prevent itsrequest from colliding with requests from other UEs. A contention-freerandom access procedure can be performed when the UE 504 is in an RRCconnected mode before the random access procedure, such as in the caseof a handover.

FIG. 6 illustrates an example two-step random access procedure 600,according to aspects of the disclosure. The two-step random accessprocedure 600 may be performed between a UE 604 (e.g., any of the UEsdescribed herein) and a base station 602 (illustrated as a gNB), whichmay correspond to any of the UEs and base stations, respectively,described herein.

At 610, the UE 604 transmits a RACH Message A (“MsgA”) to the basestation 602. In a two-step random access procedure 600, Msg1 and Msg3,described above with reference to FIG. 5 , are collapsed (e.g.,combined) into MsgA and sent to the base station 602. As such, a MsgAincludes a RACH preamble and a PUSCH, similar to the Msg3 PUSCH of afour-step RACH procedure. The RACH preamble may have been selected from64 possible preambles, as described above with reference to FIG. 5 , andmay be used as a reference signal for demodulation of the datatransmitted in the MsgA. At 620, the UE 604 receives a RACH Message B(“MsgB”) from the base station 602. The MsgB may be a combination ofMsg2 and Msg4 described above with reference to FIG. 5 .

The combination of Msg1 and Msg3 into one MsgA and the combination ofMsg2 and Msg4 into one MsgB allows the UE 604 to reduce the RACHprocedure setup time to support the low-latency requirements of 5G NR.Although the UE 604 may be configured to support the two-step randomaccess procedure 600, the UE 604 may still support the four-step randomaccess procedure 500 as a fall back if the UE 604 is not be able to usethe two-step random access procedure 600 due to some constraints (e.g.,high transmit power requirements, etc.). Therefore, a UE in 5G/NR may beconfigured to support both the two-step and the four-step random accessprocedures, and may determine which random access procedure to configurebased on the RACH configuration information received from the basestation.

After the random access procedure 500/600, the UE 504/604 is in an RRCconnected state. The RRC protocol is used on the air interface between aUE and a base station. The major functions of the RRC protocol includeconnection establishment and release functions, broadcast of systeminformation, radio bearer establishment, reconfiguration and release,RRC connection mobility procedures, paging notification and release, andouter loop power control. In LTE, a UE may be in one of two RRC states(connected or idle), and in NR, a UE may be in one of three RRC states(connected, idle, or inactive). The different RRC states have differentradio resources associated with them that the UE can use when it is in agiven state.

FIG. 7 is a diagram 700 of the different RRC states (also referred to asRRC modes) in NR, according to aspects of the disclosure. When a UE ispowered up, it is initially in the RRC disconnected/idle state 710.After the random access procedure 500 or 600, it moves to the RRCconnected state 720. If there is no activity from UE for a short time,it can suspend its session by moving to the RRC inactive state 730. TheUE can resume its session by performing a random access procedure 500 or600 to transition back to the RRC connected state 720. Thus, the UEneeds to perform a random access procedure 500 or 600 to transition tothe RRC connected state 720, regardless of whether the UE is in the RRCidle state 710 or the RRC inactive state 730.

The operations performed in the RRC idle state 710 include public landmobile network (PLMN) selection, broadcast of system information, cellre-selection mobility, paging for mobile terminated data (initiated andmanaged by the 5GC), discontinuous reception (DRX) for core networkpaging (configured by NAS). The operations performed in the RRCconnected state 720 include 5GC (e.g., 5GC 260) and New RAN (e.g., NewRAN 220) connection establishment (both control and user planes), UEcontext storage at the New RAN and the UE, New RAN knowledge of the cellto which the UE belongs, transfer of unicast data to/from the UE, andnetwork controlled mobility. The operations performed in the RRCinactive state 730 include the broadcast of system information, cellre-selection for mobility, paging (initiated by the New RAN), RAN-basednotification area (RNA) management (by the New RAN), DRX for RAN paging(configured by the New RAN), 5GC and New RAN connection establishmentfor the UE (both control and user planes), storage of the UE context inthe New RAN and the UE, and New RAN knowledge of the RNA to which the UEbelongs.

In some cases, the UE may transition from the RRC connected state 720 tothe RRC idle state 710 or the RRC inactive state 730 during an ongoingpositioning session, such as a multi-round-trip-time (multi-RTT) session(which may be uplink-only or downlink-and-uplink), an uplink timedifference of arrival (UL-TDOA) session (uplink-only), an uplinkangle-of-arrival (UL-AoA) session (uplink-only), and the like.

In an RTT procedure, an initiator (a base station or a UE) transmits anRTT measurement signal (e.g., a PRS or SRS) to a responder (a UE or basestation), which transmits an RTT response signal (e.g., an SRS or PRS)back to the initiator. The RTT response signal includes the differencebetween the ToA of the RTT measurement signal and the transmission timeof the RTT response signal, referred to as the reception-to-transmission(Rx-Tx) measurement. The initiator calculates the difference between thetransmission time of the RTT measurement signal and the ToA of the RTTresponse signal, referred to as the “Tx-Rx” measurement. The propagationtime (also referred to as the “time of flight”) between the initiatorand the responder can be calculated from the Tx-Rx and Rx-Txmeasurements. Based on the propagation time and the known speed oflight, the distance between the initiator and the responder can bedetermined. For multi-RTT (also referred to as “multi-cell-RTT”)positioning, a UE performs an RTT procedure with multiple base stationsto enable its location to be triangulated based on the known locationsof the base stations. RTT and multi-RTT methods can be combined withother positioning techniques, such as UL-AoA and DL-AoD, to improvelocation accuracy.

In an UL-TDOA session, the UE transmits uplink reference signals (e.g.,SRS) that are received by a reference base station and one or morenon-reference base stations. The base stations report the times ofarrival (ToAs) of the uplink reference signals to a positioning entity(e.g., the UE, the serving base station, location server 230, LMF 270,SLP 272), which calculates the reference signal time difference (RSTD)of the uplink reference signals between the reference base station andeach non-reference base station. Based on the known locations of theinvolved base stations and the RSTD measurements, the positioning entitycan estimate the UE's location.

Unlike multi-RTT and UL-TDOA positioning methods, which require three ormore base stations to measure signals from the UE, an UL-AoA session canbe performed between a UE and a single base station. In an UL-AoAprocedure, For UL-AoA positioning, a base station measures the angle andother channel properties (e.g., gain level) of the uplink receive beamused to communicate with a UE to estimate the location of the UE. The UEand the base station may also perform an RTT procedure to further refinethe location estimate.

There are various reasons that a UE may transition from the RRCconnected state 720 to the RRC idle state 710 or the RRC inactive state730 during an ongoing positioning session. For example, the DRX cyclewith which the UE has been configured may call for the UE to transitioninto the RRC inactive state 730, or the UE's serving base station mayinstruct the UE to transition into the RRC inactive state 730, or the UEmay become disconnected from the network for some reason and transitionto the RRC idle state 710. Whatever the reason, it would be beneficialfor the UE to be able to leverage the subsequent random access procedure500 or 600 to continue the ongoing positioning session before the UEtransitions back to the RRC connected state 720.

Accordingly, there are techniques for associating SRS resources to RACHresources for a UE in an RRC idle state 710 or an RRC inactive state 730during an uplink-only (e.g., UL-AoA, UL-TDOA) or uplink-downlink (e.g.,RTT) positioning session. FIG. 8 is a diagram 800 of an examplepositioning procedure between a UE 804 and two TRPs 802-1 and 802-2(collectively, TRPs 802), according to aspects of the disclosure. The UE804 may correspond to any of the UEs described herein, and the TRPs 802may correspond to (or be TRPs of) any of the base stations describedherein. The positioning session may be a multi-RTT session, an UL-TDOAsession, an UL-AoA session, or the like.

During a first RRC connected state 810 (which may correspond to the RRCconnected state 720), the UE 804 is configured with a first set of oneor more SRS resources on which to transmit one or more SRS 812 to theTRPs 802 for the positioning session. Specifically, the UE 804 isconfigured with one or more SRS resources on which to transmit one ormore SRS 812-1 (labeled “SRS1”) to the TRP 802-1, and with one or moreSRS resources on which to transmit one or more SRS 812-2 (labeled“SRS2”) to the TRP 802-2. In an aspect, the one or more SRS resourcesmay be an SRS resource set.

While in the first RRC connected state 810, the UE 804 obtains a firstassociation of at least one SRS resource (or at least one SRS resourceset) of the one or more SRS resources to at least one RACH resource ofone or more RACH resources for each TRP 802. More specifically, the UE804 obtains an association of at least one SRS resource (or at least oneSRS resource set) of the one or more SRS resources on which the one ormore SRS 812-1 were transmitted to at least one RACH resource of one ormore RACH resources allocated for transmission of RACH messages (e.g.,Msg1, Msg3, MsgA) to the TRP 802-1. Similarly, the UE 804 obtains anassociation of at least one SRS resource (or at least one SRS resourceset) of the one or more SRS resources on which the one or more SRS 812-2were transmitted to at least one RACH resource of one or more RACHresources allocated for transmission of RACH messages (e.g., Msg1, Msg3,MsgA) to the TRP 802-2. The UE 804 may receive (be configured with) theassociations from the serving TRP (e.g., one of TRP 802-1 and 802-2) orthe respective TRPs 802-1 and 802-2. In an aspect, the association maybe received with the SRS resource configuration or in a separatetransmission. The at least one SRS resource may be, for example, one ormore SRS resources, an SRS resource set, or the like.

Subsequently, the UE 804 transitions to an RRC idle state or an RRCinactive state 820. This may be, for example, due to a command from theserving TRP (e.g., one of TRPs 802-1 and 802-2), the expiration of a DRXtimer, or the like. When the UE 804 determines to switch from the RRCidle/inactive state 820 to a second RRC connected state 830, it uses theconfigured association between the SRS resources (or SRS resource sets)and the RACH resources received during the RRC connected state 810 totransmit the RACH message(s) 822 (e.g., a Msg1 and Msg3, or a MsgA) ofthe associated random access procedures (e.g., random access procedure500/600). More specifically, the UE 804 transmits the RACH message(s)822-1 (e.g., a Msg1 and Msg3 or a MsgA) to the TRP 802-1 usingtransmission properties inherited from at least one associated SRSresource (or SRS resource set) on which the SRS 812-1 was/weretransmitted. Similarly, the UE 804 transmits the RACH message(s) 822-2(e.g., a Msg1 and Msg3 or a MsgA) to the TRP 802-2 using transmissionproperties inherited from at least one associated SRS resource (or SRSresource set) on which the SRS 812-2 was/were transmitted. The TRPs 802measure the RACH messages on the associated RACH resources as they wouldan SRS-for-positioning resource (e.g., ToA, AoA, etc.). The transmissionproperties inherited from the at least one associated SRS resource mayinclude an uplink spatial transmit filter of the at least one SRSresource, a path-loss reference resource, path-loss estimate, and/ortransmission power estimate of the at least one SRS resource, atransmission timing of the at least one SRS resource, a subcarrierspacing (SCS), a duration, and/or a transmission bandwidth of the atleast one SRS resource. Note that a MsgA contains a RACH preamble andPUSCH, and the PUSCH carries DMRS. As such, if the RACH message(s) 822are MsgAs, either the preamble or the DMRS or both can be used forpositioning.

More specifically, in an aspect, the configured association may relatean uplink spatial transmit filter (also referred to as an uplinktransmit beam) of the at least one SRS resource (or SRS resource set) tothe at least one RACH resource. In that case, the UE 804 can transmit aPRACH preamble (e.g., a PRACH preamble for Msg1 or MsgA) on the at leastone RACH resource using the uplink spatial transmit filter of the atleast one SRS resource. Additionally or alternatively, the configuredassociation may relate a path-loss reference resource, path-lossestimate, and/or transmission power estimate of the at least one SRSresource (or SRS resource set) to the at least one RACH resource. Inthat case, the UE 804 can transmit a PRACH preamble on the at least oneRACH resource using the transmission power estimate, path-loss estimate,and/or the path-loss reference resource of the at least one SRSresource. Additionally or alternatively, the configured association mayrelate a transmission timing of the at least one SRS resource (or SRSresource set) with the at least one RACH resource. In that case, the UE804 can transmit a PRACH preamble on the at least one RACH resourceusing the transmission timing of the at least one SRS resource.Additionally or alternatively, the configured association may relate afirst SCS, a first duration, and/or a first transmission bandwidth ofthe at least one SRS resource (or SRS resource set) with the at leastone RACH resource. In that case, the UE 804 can transmit a PRACHpreamble on the at least one RACH resource using a second SCS, a secondduration, and/or a second transmission bandwidth that is based on thefirst SCS, the first duration, and/or the first transmission bandwidthof the at least one SRS resource.

Referring to the SCS, duration, and/or transmission bandwidth of the atleast one SRS resource (or SRS resource set) in more detail, the atleast one SRS resource may have a difference SCS, duration, and/ortransmission bandwidth than is permitted for a RACH resource. As such,there may need to be a mapping between the SCS of the at least one SRSresource and the SCS of the at least one RACH resource, the duration ofthe at least one SRS resource and the duration of the at least one RACHresource, and/or the transmission bandwidth of the at least one SRSresource and the transmission bandwidth of the at least one RACHresource. Such mappings may be defined by the relevant standard. Thesemappings may take the form of one or more rules. For example, a rule maystate that if the duration of the at least one SRS resource is greaterthan ‘X,’ then select ‘Y’ for the duration of the at least one RACHresource.

When the UE 804 transmits the RACH messages 822, it needs to identifyitself to the receiving TRP 802 in each RACH resource. To do this, as afirst option, each TRP 802 may be provided a one-to-one mapping of aRACH occasion to a UE. That is, each UE (e.g., UE 804) would beassociated with its own RACH occasions(s). This mapping may be providedby the location server (e.g., location server 230, LMF 270, SLP 272) ora TRP (e.g., the serving TRP). As a second option, an identifier of theUE 804 could be conveyed to the network in the Msg3 or MsgA payload. Asa third option, there may be some association of the UE 804 to therespective RACH resources. For example, a RACH preamble index may bemapped to a specific UE. This information could be provided by eitherthe location server or a TRP (e.g., the serving TRP). As a fourthoption, a group of UEs could be associated with a set of one or moreRACH resources, one or more RACH occasions, one or more RACH preambleindexes, or any combination thereof, and the UE 804 may provide ashorter identifier in the RACH message payload that uniquely identifiesthe UE 804 within that group. Again, this mapping could be provided bythe location server or a TRP (e.g., the serving TRP).

There may also need to be a triggering mechanism to inform the involvedTRPs (here, TRPS 802-1 and 802-2) to monitor for the associated RACHresources instead of the SRS-for-positioning resources. As a firstoption, the serving TRP (e.g., one of TRP 802-1 and 802-2) may informthe location server (e.g., location server 230, LMF 270, SLP 272), whichmay inform the neighboring TRPs (e.g., the other of TRP 802-1 and802-2). As a second option, the serving TRP may inform the neighboringTRPs directly over a backhaul link.

After the random access procedures (e.g., random access procedure500/600) with the TRPs 802, the UE 804 is in a second RRC connectedstate 830 (e.g., RRC connected state 720). At this time, the UE 804 isconfigured (by, e.g., the location server 230, LMF 270, SLP 272) with anew set of one or more SRS resources (or SRS resource sets) forpositioning purposes for each TRP 802. The UE 804 continues thepositioning session by transmitting one or more SRS 832-1 to the TRP802-1 on the newly configured SRS resources for the TRP 802-1, andtransmitting one or more SRS 832-2 to the TRP 802-2 on the newlyconfigured SRS resources for the TRP 802-2. Sometime after entering thesecond RRC connected state 830, the UE 804 may receive a secondassociation of at least one SRS resource (or SRS resource set) of theset of one or more SRS resources allocated for each TRP 802 to at leastone RACH resource of one or more RACH resources allocated for each TRP802. Again, the UE 804 may receive the association from the serving TRP(e.g., one of TRP 802-1 and 802-2) or from the respective TRPs 802. TheUE 804 may store this association until the next time it transitions tothe RRC idle or disconnected state during the same positioning session.Thus, as will be appreciated, the UE 804 may repeat the above operationsuntil the positioning session is complete.

Because the RACH message(s) 822 are transmitted as part of an ongoingpositioning session, the TRPs 802 perform positioning measurements(e.g., ToA, AoA) of the SRS 812, the RACH message(s) 822, and the SRS832. The TRPs 802 may then report these measurements to a positioningentity, such as a location server (e.g., location server 230, LMF 270,SLP 272), the UE 804 (for UE-based positioning), or the serving TRP(e.g., one of TRPs 802-1 and 802-2). If the positioning session is amulti-RTT session, the TRPs 802 may transmit downlink reference signalsin response to the received SRS 812, the RACH message(s) 822, and theSRS 832. As is known in the art, the payloads of these response signalsmay include the amount of time between the reception of the SRS 812, theRACH message(s) 822, and the SRS 832 and the transmission of theresponse signals (i.e., the TRPs' 802 Rx-Tx measurements).Alternatively, the TRPs 802 may transmit this information to thepositioning entity. The location of the UE 804 can then be estimatedusing known techniques.

As will be appreciated, the various network nodes described above maycommunicate over different interfaces and using different protocols. Forexample, the UE 804 may communicate with the location server, and viceversa, using LTE positioning protocol (LPP) signaling. The TRPs 802 maycommunicate with the location server using LTE positioning protocol typeA (LPPa) or NR positioning protocol type A (NRPPa) signaling. The TRPs802 may communicate with each other over a backhaul connection (e.g.,backhaul connection 223). The UE 804 may communicate with the TRPs 802using a wireless cellular protocol, such as the LTE or NR protocol.

There are currently two RACH preamble lengths, RACH preambles having alength of 839 (referred to as “long” preambles or sequences), and RACHpreambles having a length of 139 (referred to as “short” preambles orsequences). In addition, long preambles use four preamble formats, whileshort preambles use nine preamble formats. FIG. 9 is a graph 900illustrating the different preamble lengths and formats. As can be seenin FIG. 9 , the four formats of the long preambles are numbered ‘0’ to‘3,’ and the nine formats of the short preambles are numbered “A1” to“A3,” “B1” to “B4,” and “C0” and “C2.” Each row of graph 900 is an RO.Each RO begins with a cyclic prefix of some length (represented as “C”),has one or more repetitions of the preamble sequence (represented as“S”), and ends with a guard period of some length (represented as “G”).For reference, the last row of graph 900 illustrates a subframe of aPUSCH for 15 kHz subcarrier spacing. As such, the subframe comprises oneslot having a length of 1 ms and divided into 14 symbols (see Table 1).

The four formats for the long preambles are designed for large (i.e.,macro) cell deployments in FR1, and are typically used in frequencybands below 6 GHz. The preamble format (i.e., ‘0’ to ‘3’) is part of thecell's random-access configuration (broadcasted in the SIB), and eachcell is generally limited to a single preamble format. In NR, thenumerology used for long preambles is different from other NRtransmissions, as the origin of long preambles is partly from thepreambles used for LTE. For example, preamble formats ‘0’ and ‘1’ in NRare the same as preamble formats ‘0’ and ‘2’ in LTE. Preambles can use asubcarrier spacing of 1.25 kHz or 5 kHz. A long preamble with 1.25 kHzsubcarrier spacing occupies six resource blocks in the frequency domain,while a preamble with five kHz subcarrier spacing occupies 24 resourceblocks.

Short preambles are, in general, shorter than the long preambles, andoften span only a few OFDM symbols (as shown in FIG. 9 ). The nineformats of the short preambles are designed for small cell deployments,including indoor coverage. These preamble formats can be used for bothFR1 and FR2 ranges. The subcarrier spacing for short preambles isaligned with the normal NR subcarrier spacing (e.g., 15 kHz, 30 kHz, 60kHz, and 120 kHz). In FR1, short preambles use 15 or 30 kHz subcarrierspacing, whereas in FR2, short preambles use 60 or 120 kHz subcarrierspacing. A short preamble occupies 12 resource blocks in the frequencydomain, regardless of the preamble numerology.

Short preamble formats are designed such that the last part of each OFDMsymbol acts as a cyclic prefix for the next OFDM symbol, and the lengthof a preamble OFDM symbol equals the length of a data OFDM symbol. Inmost cases, it is therefore possible to have multiple preambletransmissions multiplexed in time within a single RACH slot (where thereare a configured number of RACH slots per data slot, see FIG. 10 below).In other words, for short preambles, there can be multiple ROs in thefrequency domain as well as in the time domain within a single RACH slot(also referred to as a “PRACH slot”). Note, however, that a RACH slot isnot necessarily commensurate with a data slot, as illustrated below withreference to FIG. 10 .

NR supports a mix of the “A” and “B” preamble formats to enableadditional formats such as “A1/B1,” “A2/B2,” and “A3/B3.” Short preambleformats “A” and “B” are identical except for somewhat shorter cyclicprefixes for the “B” formats. Preamble formats “B2” and “B3” are used incombination with the corresponding “A” formats (i.e., “A2” and “A3”).

Short preambles allow the base station receiver to use the same FFT fordata and random access preamble detection. These preambles are acomposition of multiple shorter OFDM symbols per PRACH preamble, makingthem more robust against time varying channels and frequency errors.Short preambles also support analog beam sweeping during PRACH receptionsuch that the same preamble can be received with different beams at thebase station.

FIG. 10 is a diagram 1000 of an example allocation of ROs in the timedomain. In the example of FIG. 10 , there are two 120 kHz slots(numbered ‘7’ and ‘8’), which span one 60 kHz slot. Table 3 below showsthe time domain configuration parameters for the specific allocation ofROs illustrated in FIG. 10 . The parameters in Table 3 result in theallocation of ROs shown in FIG. 10 .

TABLE 3 Number of Number of RACH Time Slots Domain within ROs withinPreamble Slot Starting a 60 kHz a RACH RACH Format Number Symbol SlotSlot Duration A1 7, 15, 23, 0 2 6 2 31, 39

Thus, from Table 3 and as shown in FIG. 10 , there are two 120 kHz RACHslots (slots ‘7’ and ‘8’) within a single 60 kHz slot, and ROs (theshaded symbols) start at symbol 0 of slot ‘7.’ Each RO is of format“A1,” and is therefore two symbols in duration (see graph 900 of FIG. 9). There are six ROs within each slot, for a total of 12 consecutivesymbols per slot.

For the frequency domain configuration, the frequency domain location(i.e., the frequency domain resource) for a RACH preamble is determinedby the RRC parameters “msg1-FDM” and “msg1-FrequencyStart.” Theparameter “msg1-FDM” can take a value of {1, 2, 4, 8}. The parameter“msg1-FrequencyStart” is an integer from ‘1’ to the maximum number ofPRBs minus one. The time domain location (i.e., the time domainresource) for a RACH preamble is determined by the RRC parameter“prach-ConfigurationIndex,” which is an integer from 0 to 255.

In NR, each synchronization signal (i.e., the SSB) is associated with adifferent downlink transmit beam and the UE can select a certainsynchronization signal beam and send the PRACH (i.e., the preamble)using an uplink transmit beam based on the selected downlink transmitbeam. In order for the network to determine which beam the UE hasselected, there is a specific mapping between an SSB and RO. Bydetecting on which RO the UE sent the PRACH, the network can determinewhich SSB/beam the UE selected. The mapping between SSB and RO isdefined by the RRC parameters “msg1-FDM” and“ssb-perRACH-OccasionAndCB-PreamblesPerSSB.” The parameter “msg1-FDM”specifies how many ROs are allocated in the frequency domain at the samelocation in the time domain. The parameter“ssb-perRACH-OccasionAndCB-PreamblesPerSSB” specifies how many SSBs canbe mapped to one RO and how many preamble indexes can be mapped to asingle SSB.

FIGS. 11A to 11D illustrate various examples of RO allocations in thetime and frequency domains. In the example diagram 1100A of FIG. 11A,“msg1-FDM” equals ‘1’ and “ssb-perRACH-OccasionAndCB-PreamblesPerSSB”equals ‘1.’ In the example diagram 1100B of FIG. 11B, “msg1-FDM” equals‘2’ and “ssb-perRACH-OccasionAndCB-PreamblesPerSSB” equals ‘1.’ In theexample diagram 1100C of FIG. 11C, “msg1-FDM” equals ‘2’ and“ssb-perRACH-OccasionAndCB-PreamblesPerSSB” equals ‘8.’ In the examplediagram 1100D of FIG. 11D, “msg1-FDM” equals ‘2’ and“ssb-perRACH-OccasionAndCB-PreamblesPerSSB” equals ‘½.’

As described above, a short preamble occupies 12 PRBs in the frequencydomain regardless of the preamble numerology. This is small compared tothe bandwidth of an SRS-for-positioning. As such, when using a RACHpreamble for positioning purposes, it would be beneficial to increasethe bandwidth of the RACH preamble transmission to make it morecommensurate with the bandwidth of an SRS-for-positioning. Accordingly,the present disclosure provides techniques to associate one SRS resource(or SRS resource set) to multiple RACH resources or multiple ROs toincrease the transmitted bandwidth of the RACH preamble, and thereforethe measurement resolution at the base station and the accuracy of thepositioning estimate using the RACH preamble. More specifically, a UEmay be configured with an association of one SRS resource (or SRSresource set) to multiple RACH resources or multiple ROs on differentbandwidths, where the UE transmits each RACH preamble with the sameantenna port in adjacent transmission opportunities.

FIG. 12 is a diagram 1200 of an example positioning session between a UE1204 and two TRPs (both numbered 1202 and labeled “TRP1” and “TRP2”),according to aspects of the disclosure. The UE 1204 may correspond toany of the UEs described herein, and the TRPs may be TRPs of any of thebase stations described herein. In FIG. 12 , time is representedhorizontally and frequency is represented vertically. The positioningsession may be a multi-RTT session, an UL-TDOA session, an UL-AoAsession, or the like. FIG. 12 illustrates two TRPs 1202 to indicate thatthere may be a plurality of TRPs and that the SRS and corresponding RACHresources may be received by the plurality of TRPs. Thus, the disclosuredoes not require, and is not limited to, two TRPs 1202 as illustrated.

During a first RRC connected state 1210 (e.g., RRC connected state 720),the UE 1204 is configured with an SRS resource 1212 (or SRS resourceset) on which to transmit a first SRS-for-positioning (labeled “SRS1”)to the TRPs 1202. While in the RRC connected state 1210, the UE 1204obtains an association of the SRS resource 1212 (or SRS resource set) tomultiple RACH resources 1222 (labeled “RACH1,” “RACH2,” “RACH3”) for theTRPs 1202. More specifically, the UE 1204 obtains an association of theSRS resource 1212 (or SRS resource set) on which it transmitted theSRS-for-positioning to multiple RACH resources 1222 allocated fortransmission of RACH signal(s)/message(s) (e.g., Msg1, Msg3, MsgA) tothe TRPs 1202. In an aspect, the UE 1204 may receive (be configuredwith) the associations from the serving TRP (e.g., “TRP1” 1202). In anaspect, the association may be received with the SRS resourceconfiguration or in a separate transmission.

Subsequently, the UE 1204 transitions to an RRC idle state or an RRCinactive state 1220 (e.g., RRC idle state 710 or RRC inactive state 730,respectively). This may be, for example, due to a command from theserving TRP (e.g., “TRP1” 1202), the expiration of a DRX timer, or thelike. Before the UE 1204 switches from the RRC idle/inactive state 1220back to the RRC connected state 1210, it uses the configured associationbetween the SRS resource 1212 (or SRS resource set) and the multipleRACH resources 1222 received during the previous RRC connected state1210 to transmit RACH signal(s)/message(s) (e.g., a Msg1 and Msg3, or aMsgA) for the random access procedure (e.g., random access procedure500/600) necessary to transition back to the RRC connected state 1210.More specifically, the UE 1204 transmits the RACH message(s) (e.g., aMsg1 and Msg3, or a MsgA) to the TRPs 1202 using transmission propertiesinherited from the associated SRS resource 1212 (or SRS resource set) onwhich the previous SRS-for-positioning (“SRS1”) was transmitted. Thetransmission properties inherited from the associated SRS resource 1212(or SRS resource set) may be the same as described above with referenceto FIG. 8 . The TRPs 1202 measure the RACH signal(s)/message(s) on theassociated multiple RACH resources 1222 as they did theSRS-for-positioning (e.g., ToA, UL-AoA, etc.).

In an aspect, the associated multiple RACH resources 1222 shouldcorrespond to ROs that have different frequency bandwidths, but thatcover a contiguous bandwidth after they are all processed together. Theassociated multiple RACH resources 1222 should also correspond to ROsthat occur in consecutive time instances without a gap in between, orwith a gap that is less than a specified threshold. In this case, thethreshold should be such that no other channel is expected to betransmitted within the gap period. These time and frequency constraintsare illustrated in FIG. 12 by the “stair stepping” of the multiple RACHresources 1222. Note that in general, only ROs within the same RACH slotcan be assumed to be coherently transmitted (i.e., the same antenna portis used). In addition, only ROs within the RACH slots of the samesubframe for FR1 (or 60 kHz slots for FR2) can be assumed to becoherently transmitted. Further, the associated multiple RACH resources1222 should correspond to ROs that are transmitted through the sametransmission port of the UE, are spatially transmit quasi-co-located(i.e., use the same transmit beam), have the same transmit power, and/orhave the same timing.

After a random access procedure (e.g., random access procedure 500/600)with the TRPs 1202, the UE 1204 is in a second RRC connected state 1210(e.g., RRC connected state 720). At this time, the UE 1204 is configured(by, e.g., the location server 230, LMF 270, SLP 272) with new SRSresources 1232 (or SRS resource sets) for positioning purposes for theTRPs 1202. The UE 1204 continues the positioning session by transmittingan SRS-for-positioning to the TRPs 1202 on the newly configured SRSresources 1232 (or SRS resource sets). Sometime after entering thesecond RRC connected state 1210, the UE 1204 may obtain a secondassociation of one SRS resource 1232 (or one SRS resource set) tomultiple RACH resources allocated for the TRPs 1202. Again, the UE 1204may obtain the association from the serving TRP. The UE 1204 may storethis association until the next time it transitions to the RRC idle orinactive state during the same positioning session. Thus, as will beappreciated, the UE 1204 may repeat the above operations until thepositioning session is complete.

Because the RACH message(s) on the multiple RACH resources 1222 aretransmitted as part of an ongoing positioning session, the TRPs 1202perform positioning measurements (e.g., ToA, UL-AoA) of theSRS-for-positioning transmitted on the SRS resource 1212 (or SRSresource set), the RACH message(s) transmitted on the multiple RACHresources 1222, and the SRS-for-positioning transmitted on the SRSresource 1232 (or SRS resource set). The TRPs 1202 may then report thesemeasurements to a positioning entity, such as a location server (e.g.,location server 230, LMF 270, SLP 272), the UE 1204 (for UE-basedpositioning), or the serving TRP. If the positioning session is amulti-RTT session, the TRPs 1202 may transmit downlink reference signalsin response to the received SRS-for-positioning transmitted on the SRSresource 1212 (or SRS resource set), the RACH message(s) transmitted onthe multiple RACH resources 1222, and the SRS-for-positioningtransmitted on the SRS resource 1232 (or SRS resource set). As is knownin the art, the payloads of these response signals may include theamount of time between the reception of the SRS-for-positioningtransmitted on the SRS resource 1212, the RACH message(s) transmitted onthe multiple RACH resources 1222, and the SRS-for-positioningtransmitted on the SRS resource 1232 and the transmission of theresponse signals. Alternatively, the TRPs 1202 may transmit thisinformation to the positioning entity. The location of the UE 1204 canthen be estimated using known techniques.

FIGS. 13A to 13C are diagrams of example configurations of ROs,according to aspects of the disclosure. In each figure, the “msg1-FDM”parameter (which specifies how many ROs are allocated in the frequencydomain at the same location in the time domain) is ‘4’ and the“ssb-perRACH-OccasionAndCB-PreamblesPerSSB” (which specifies how manySSBs can be mapped to one RO and how many preamble indexes can be mappedto a single SSB) is ‘4.’ In addition, time is represented horizontallyand frequency is represented vertically. As such, in each figure, thereare four ROs vertically and four ROs horizontally. The length of each ROin the time domain is the number of symbols of the RO format, as shownin FIG. 9 . The height of each RO in the frequency domain is the numberof PRBs for that RO format and that numerology. For example, a longpreamble with 1.25 kHz numerology occupies six PRBs, while a preamblewith 5 kHz numerology occupies 24 PRBs.

In an aspect, there may be four ROs in the group of RACH resources thatis associated with an SRS resource (or SRS resource set). In an aspect,the indexes of the ROs can be configured explicitly, for example, {0, 5,10, 15}, {4, 9, 14, 3}, etc. Alternatively, there may be a specifiedpattern defining how the ROs are to be sounded, and thus, only the firstindex of an RO may need to be provided for each group. In an aspect, anSRS resource may be associated with only one RO in a group (e.g., thefirst RO that the UE is expected to transmit), but the UE may alsotransmit the remaining ROs of the group.

FIG. 13A is a diagram 1300A illustrating a first example configurationof ROs. In FIG. 13A, a first group of RACH resources comprises the ROsnumbered 3, 4, 9, 14, a second group of RACH resources comprises the ROsnumbered 2, 7, 8, 13, a third group of RACH resources comprises the ROsnumbered 1, 6, 11, 12, and a fourth group of RACH resources comprisesthe ROs numbered 0, 5, 10, 15. Since the groups of ROs form a diagonalpattern, a UE could be configured with just the index values of thefirst RO in each group, and could derive the remaining index values fromthe knowledge that the next RO in the group will be diagonal from theprevious one. Alternatively, the UE may be configured with each indexvalue. As will be appreciated, more than one RO-group-creation principlecan be specified.

FIG. 13B is a diagram 1300B illustrating a second example configurationof ROs. In FIG. 13B, a first group of RACH resources comprises the ROsnumbered 2, 4, 10, 13, a second group of RACH resources comprises theROs numbered 0, 6, 9, 15, a third group of RACH resources comprises theROs numbered 3, 5, 11, 12, and a fourth group of RACH resourcescomprises the ROs numbered 1, 7, 8, 14. Since the groups of ROs do nothave any particular pattern, the UE may be configured with each indexvalue of each RO in a group.

As can be seen in FIGS. 13A and 13B, the ROs in a group are adjacent inthe time domain (the horizontal axis) and, when processed at thereceiving base station (or TRP), will be contiguous in the frequencydomain as well. Said another way, the group of ROs spans multipleadjacent frequency resources (e.g., PRBs) over multiple adjacent timeresources (e.g., symbols, slots).

For some UEs, based on their capabilities, it may be possible for themto transmit multiple ROs on the same OFDM symbol. In that case, a groupof ROs associated with an SRS resource (or SRS resource set) can be onthe same symbol. This is shown in FIG. 13C. FIG. 13C is a diagram 1300Cillustrating an example configuration of ROs across consecutive symbols.In FIG. 13C, a first group of RACH resources comprises the ROs numbered0-3, a second group of RACH resources comprises the ROs numbered 4-7, athird group of RACH resources comprises the ROs numbered 8-11, and afourth group of RACH resources comprises the ROs numbered 12-15. Eachgroup, despite having a length of one symbol, is associated with adifferent SRS resource. Note that while the groups of ROs are associatedwith the particular SRS resources, it does not mean that they are thesame length as the associated SRS resource.

In further aspects of the disclosure, for different RACH formats, adifferent number of repetitions across frequency can be considered. Forexample, for format ‘2’ (for a long preamble), which already spans morethan 3 ms (see FIG. 9 ), it may not be possible to associate one SRSresource with multiple RACH occasions. However, for format “B1” (for ashort preamble), which is only 4 symbols for 30 kHz subcarrier spacing,there can be multiple (e.g., 7) such repetitions within a subframe,which would result in a total RACH bandwidth of 84 RBs (i.e., 7*12=84RBs) for 30 kHz subcarrier spacing, which is a total bandwidth of 30 MHzfor the group of ROs.

In an aspect, in each RO of a group of ROs associated with an SRSresource, the UE may be configured with one preamble index value or asequence of preamble index values. If the UE is configured with onepreamble index value (having a value of 0 to 63 because there are 64preambles), the UE may be expected to use that preamble index value forall ROs of the group. If the UE is configured with a sequence ofpreamble index values, and there are as many preamble index values asthere are ROs in the group, the UE may be expected to transmit eachpreamble index in each RO. If the UE is configured with a sequence ofpreamble index values, and there are fewer preamble index values thanthere are ROs in the group, the UE can randomly (for example) select apreamble index for each RO of the group of ROs.

In an aspect, the same RO can be shared between positioning and regularRACH. To differentiate between a positioning RACH and a regular RACH, aUE can use a different RACH preamble index and/or RACH configurationindex depending on the type of RACH (i.e., positioning or regular).Alternatively or additionally, a new RACH configuration index could beadded such that positioning RACH and regular RACH can coexist. Note thatin this aspect, the same UE may use the same RO for both positioning andregular RACH, or different UEs may use the same RO, some forpositioning, others for regular RACH.

In the case that a UE is using the same RACH resources for bothpositioning and initial access, the UE would need to add thisinformation to the msgA or Msg3. For example, if the RACH resource is ashared resource, the UE could provide this information in the messagepayload. For example, a “1” could mean “initial access,” a “2” couldmean “positioning,” and a “3” could mean “both.” As will be appreciatedhowever, this is merely an example of how to convey this information. Inthe case of “both,” the UE does not need to add the positioninginformation to the payload because that would be added in the RRCconnected state. That is, if the UE is doing both initial access andpositioning, then the UE would be moving to an RRC connected state, sothere may not be a need to send the parameters during the connectedstate as part of the payload of the RACH PUSCH (in MsgA or Msg3).

In an aspect, the identification of which groups of ROs (or groups ofRACH resources) can be used for positioning or regular RACH can be aconfiguration that is common across cells. This means that a UE receivesthe configuration of the types of groups of RACH resources from a basestation through, for example, the SIB1 from the serving cell. Then, allthe SRS resources that are configured when the UE is in the RRCconnected state would contain a cell identifier and a RACH resourcegroup identifier that points to the common RACH resource configuration.

Note that a UE may be configured in the various ways described above bymeans of SIBs broadcasted to all UEs served in a cell, or by specificconfigurations unicast to the UE.

FIG. 14 illustrates an example method 1400 of wireless communication,according to aspects of the disclosure. The method 1400 may be performedby a UE (e.g., any of the UEs described herein).

At 1410, the UE receives, during a first state (e.g., RCC connectedstate 720), a configuration of an SRS resource or SRS resource set. Inan aspect, operation 1410 may be performed by receiver(s) 312,processing system 332, memory component 340, and/or positioning module342, any or all of which may be considered means for performing thisoperation.

At 1420, the UE obtains an association between the SRS resource or SRSresource set and a group of RACH resources. The UE may receive the firstassociation during the first state or during a previous RRC connectedstate 720. In an aspect, operation 1420 may be performed by receiver(s)312, processing system 332, memory component 340, and/or positioningmodule 342, any or all of which may be considered means for performingthis operation.

At 1430, the UE transmits, while outside the first state (e.g., while inthe RRC disconnected/idle state 710 or RRC inactive state 730), a groupof RACH signals (e.g., to at least one TRP) using transmissionproperties based on the association between the SRS resource or SRSresource set and the group of RACH resources. In an aspect, the group ofRACH resources spans a plurality of adjacent frequency resources over asingle time resource, or the group or RACH resources spans the pluralityof adjacent frequency resources over a plurality of time resources. Inan aspect, operation 1440 may be performed by transmitter(s) 314,processing system 332, memory component 340, and/or positioning module342, any or all of which may be considered means for performing thisoperation.

FIG. 15 illustrates an example method 1500 of wireless communication,according to aspects of the disclosure. The method 1500 may be performedby a TRP (e.g., a TRP of any of the base stations described herein).

At 1510, the TRP receives, from a UE (e.g., any of the UEs describedherein), an SRS on an SRS resource or SRS resource set. In an aspect,operation 1510 may be performed by receiver(s) 352, processing system384, memory component 386, and/or positioning module 388, any or all ofwhich may be considered means for performing this operation.

At 1520, the TRP receives, from the UE, a group of RACH signals havingtransmission properties based on an association between the SRS resourceor SRS resource set and a group of RACH resources on which the group ofRACH signals were received. In an aspect, the group of RACH resourcesspans a plurality of adjacent frequency resources over a single timeresource, or the group or RACH resources spans the plurality of adjacentfrequency resources over a plurality of time resources. In an aspect,operation 1520 may be performed by receiver(s) 352, processing system384, memory component 386, and/or positioning module 388, any or all ofwhich may be considered means for performing this operation.

By associating one SRS resource (or SRS resource set) to multiple RACHresources or multiple ROs, a technical advantage of the methods 1400 and1500 is to increase the transmitted bandwidth of the RACH preamble, andtherefore the measurement resolution at the base station and theaccuracy of the positioning estimate using the RACH preamble.

Implementation examples are described in the following numbered clauses:

Clause 1. A method of wireless communication performed by a UE,comprising: receiving, during a first state, a configuration of an SRSresource or SRS resource set; obtaining an association between the SRSresource or SRS resource set and a group of RACH resources; andtransmitting, while outside the first state, a group of RACH signalsusing transmission properties based on the association between the SRSresource or SRS resource set and the group of RACH resources, whereinthe group of RACH resources spans a plurality of adjacent frequencyresources over a single time resource, or the group or RACH resourcesspans the plurality of adjacent frequency resources over a plurality oftime resources.

Clause 2. The method of Clause 1, wherein the group of RACH resourcescorresponds to a plurality of RACH occasions.

Clause 3. The method of Clause 2, wherein each RACH occasion of theplurality of RACH occasions is transmitted through a same transmissionantenna port of the UE as remaining RACH occasions of the plurality ofRACH occasions.

Clause 4. The method of any of Clauses 2 and 3, wherein each RACHoccasion of the plurality of RACH occasions is spatially transmitquasi-co-located with remaining RACH occasions of the plurality of RACHoccasions, has a same transmission power as the remaining RACH occasionsof the plurality of RACH occasions, has a same timing as the remainingRACH occasions of the plurality of RACH occasions, or any combinationthereof.

Clause 5. The method of Clause 4, wherein the same transmission power isa transmission power associated with a first RACH occasion of theplurality of RACH occasions or a maximum transmission power across allof the plurality of RACH occasions.

Clause 6. The method of any of Clauses 2-5, wherein only RACH occasionswithin a same RACH slot are assumed to be transmitted on the sameantenna port.

Clause 7. The method of any of Clauses 2-6, wherein only RACH occasionswithin RACH slots of a same FR1 subframe or an FR2 slot are assumed tobe transmitted on the same antenna port.

Clause 8. The method of any of Clauses 2-7, further comprising:receiving an index value for each RACH occasion of the plurality of RACHoccasions.

Clause 9. The method of any of Clauses 2-7, further comprising:receiving an index value for a first RACH occasion of the plurality ofRACH occasions; and receiving a pattern of the plurality of RACHoccasions.

Clause 10. The method of Clause 9, wherein the association between theSRS resource or SRS resource set and the group of RACH resourcescomprises an association between the SRS resource or SRS resource setand the index value for the first RACH occasion.

Clause 11. The method of any of Clauses 2-10, further comprising:receiving one RACH preamble index for all RACH occasions of theplurality of RACH occasions.

Clause 12. The method of any of Clauses 2-10, further comprising:receiving one RACH preamble index for each RACH occasion of theplurality of RACH occasions.

Clause 13. The method of any of Clauses 2-10, further comprising:receiving a plurality of RACH preamble indexes for the plurality of RACHoccasions; and selecting one of the plurality of RACH preamble indexesfor each RACH occasion of the plurality of RACH occasions.

Clause 14. The method of any of Clauses 2-13, wherein at least one RACHoccasion of the plurality of RACH occasions is shared betweenpositioning and initial access.

Clause 15. The method of Clause 14, wherein the at least one RACHoccasion being shared between positioning and initial access isdifferentiated based on a RACH preamble index and/or a RACHconfiguration index associated with the at least one RACH occasion.

Clause 16. The method of any of Clauses 14 and 15, wherein the UEincludes an indication in the group of RACH signals that the at leastone RACH occasion is being shared between positioning and initialaccess.

Clause 17. The method of any of Clauses 1-16, wherein all RACH resourcesof the group of RACH resources has the same RACH format.

Clause 18. The method of any of Clauses 1-17, wherein: the first statecomprises an RRC connected state, and the UE being outside the firststate comprises the UE being in an RCC idle or RRC inactive state.

Clause 19. The method of any of Clauses 1-18, wherein obtaining theassociation comprises: receiving the association during the first state,or determining the association.

Clause 20. The method of any of Clauses 1-19, further comprising:receiving a configuration that the group of RACH resources can be usedfor positioning.

Clause 21. The method of any of Clauses 1-20, wherein the plurality oftime resources comprises a plurality of adjacent time resources.

Clause 22. The method of Clause 21, wherein: the plurality of frequencyresources comprises a plurality of PRBs, the single time resourcecomprises a symbol, and the plurality of adjacent time resourcescomprises a plurality of adjacent symbols or a plurality of adjacentslots.

Clause 23. The method of any of Clauses 21 and 22, wherein: timeresource of the plurality of adjacent time resources are not separatedby gaps, or are separated by gaps shorter than a threshold amount oftime, and the threshold amount of time is such that no other channel canbe transmitted during the gaps.

Clause 24. The method of any of Clauses 1-23, wherein the transmissionproperties comprise: an uplink spatial transmit filter of the SRSresource or SRS resource set, a path-loss reference resource of the SRSresource or SRS resource set, a path-loss estimate of the SRS resourceor SRS resource set, a transmission power estimate of the SRS resourceor SRS resource set, a transmission timing of the SRS resource or SRSresource set, an SCS of the SRS resource or SRS resource set, a durationof the SRS resource or SRS resource set, a transmission bandwidth of theSRS resource or SRS resource set, or any combination thereof.

Clause 25. The method of any of Clauses 1-24, wherein the group of RACHsignals comprises a group of RACH Message A, a group of RACH Message 1,a group of RACH Message 3, a group of DMRS of a RACH Message A, or agroup of DMRS of a RACH Message 3.

Clause 26. The method of any of Clauses 1-25, wherein the UE is engagedin a positioning session with the TRP.

Clause 27. The method of Clause 26, wherein the positioning sessioncomprises an UL-TDOA session, a multi-RTT session, or an UL-AoA session.

Clause 28. A method of wireless communication performed by a TRP,comprising: receiving, from a UE, an SRS on an SRS resource or SRSresource set; and receiving, from the UE, a group of RACH signals havingtransmission properties based on an association between the SRS resourceor SRS resource set and a group of RACH resources on which the group ofRACH signals were received, wherein the group of RACH resources spans aplurality of adjacent frequency resources over a single time resource,or the group or RACH resources spans the plurality of adjacent frequencyresources over a plurality of time resources.

Clause 29. The method of Clause 28, wherein the TRP is engaged in apositioning session with the UE, the method further comprising:performing a positioning measurement of the group of RACH signals.

Clause 30. The method of any of Clauses 28 and 29, wherein the group ofRACH resources corresponds to a plurality of RACH occasions.

Clause 31. The method of Clause 30, wherein each RACH occasion of theplurality of RACH occasions is transmitted through a same transmissionantenna port of the UE as remaining RACH occasions of the plurality ofRACH occasions.

Clause 32. The method of any of Clauses 30 and 31, wherein each RACHoccasion of the plurality of RACH occasions is spatially transmitquasi-co-located with remaining RACH occasions of the plurality of RACHoccasions, has a same transmission power as the remaining RACH occasionsof the plurality of RACH occasions, has a same timing as the remainingRACH occasions of the plurality of RACH occasions, or any combinationthereof.

Clause 33. The method of Clause 32, wherein the same transmission poweris a transmission power associated with a first RACH occasion of theplurality of RACH occasions or a maximum transmission power across allof the plurality of RACH occasions.

Clause 34. The method of any of Clauses 30-33, wherein only RACHoccasions within a same RACH slot are assumed to be transmitted on thesame antenna port.

Clause 35. The method of any of Clauses 30-34, wherein only RACHoccasions within RACH slots of a same FR1 subframe or an FR2 slot areassumed to be transmitted on the same antenna port.

Clause 36. The method of any of Clauses 30-35, further comprising:transmitting, to the UE, an index value for each RACH occasion of theplurality of RACH occasions.

Clause 37. The method of any of Clauses 30-35, further comprising:transmitting, to the UE, an index value for a first RACH occasion of theplurality of RACH occasions; and transmitting, to the UE, a pattern ofthe plurality of RACH occasions.

Clause 38. The method of Clause 37, wherein the association between theSRS resource or SRS resource set and the group of RACH resourcescomprises an association between the SRS resource or SRS resource setand the index value for the first RACH occasion.

Clause 39. The method of any of Clauses 30-38, further comprising:transmitting, to the UE, one RACH preamble index for all RACH occasionsof the plurality of RACH occasions.

Clause 40. The method of any of Clauses 30-38, further comprising:transmitting, to the UE, one RACH preamble index for each RACH occasionof the plurality of RACH occasions.

Clause 41. The method of any of Clauses 30-38, further comprising:transmitting, to the UE, a plurality of RACH preamble indexes for theplurality of RACH occasions to configure the UE to select one of theplurality of RACH preamble indexes for each RACH occasion of theplurality of RACH occasions.

Clause 42. The method of any of Clauses 30-41, wherein at least one RACHoccasion of the plurality of RACH occasions is shared betweenpositioning and initial access.

Clause 43. The method of Clause 42, wherein the at least one RACHoccasion being shared between positioning and initial access isdifferentiated based on a RACH preamble index and/or a RACHconfiguration index associated with the at least one RACH occasion.

Clause 44. The method of Clause 42, wherein an indication in the groupof RACH signals indicates that the at least one RACH occasion is beingshared between positioning and initial access.

Clause 45. The method of any of Clauses 28-44, wherein all RACHresources of the group of RACH resources has the same RACH format.

Clause 46. The method of any of Clauses 28-45, wherein the first statecomprises an RRC connected state.

Clause 47. The method of any of Clauses 28-46, further comprising:transmitting the association to the UE.

Clause 48. The method of any of Clauses 28-47, further comprising:transmitting, to the UE, a configuration that the group of RACHresources can be used for positioning.

Clause 49. The method of any of Clauses 28-48, wherein the plurality oftime resources comprises a plurality of adjacent time resources.

Clause 50. The method of Clause 49, wherein: the plurality of frequencyresources comprises a plurality of PRBs, the single time resourcecomprises a symbol, and the plurality of adjacent time resourcescomprises a plurality of adjacent symbols or a plurality of adjacentslots.

Clause 51. The method of any of Clauses 49 and 50, wherein: timeresource of the plurality of adjacent time resources are not separatedby gaps, or are separated by gaps shorter than a threshold amount oftime, and the threshold amount of time is such that no other channel canbe transmitted during the gaps.

Clause 52. The method of any of Clauses 28-51, wherein the transmissionproperties comprise: an uplink spatial transmit filter of the SRSresource or SRS resource set, a path-loss reference resource of the SRSresource or SRS resource set, a path-loss estimate of the SRS resourceor SRS resource set, a transmission power estimate of the SRS resourceor SRS resource set, a transmission timing of the SRS resource or SRSresource set, an SCS of the SRS resource or SRS resource set, a durationof the SRS resource or SRS resource set, a transmission bandwidth of theSRS resource or SRS resource set, or any combination thereof.

Clause 53. The method of any of Clauses 28-52, wherein the group of RACHsignals comprises a group of RACH Message A, a group of RACH Message 1,a group of RACH Message 3, a group of DMRS of a RACH Message A, or agroup of DMRS of a RACH Message 3.

Further implementation examples are described in the following numberedclauses:

Clause 1. A method of wireless communication performed by a UE,comprising: receiving, during a first state, a configuration of an SRSresource or SRS resource set; obtaining an association between the SRSresource or SRS resource set and a group of RACH resources; andtransmitting, while outside the first state, a group of RACH signals toa TRP using transmission properties based on the association between theSRS resource or SRS resource set and the group of RACH resources,wherein the group of RACH resources spans a plurality of adjacentfrequency resources over a single time resource, or the group or RACHresources spans the plurality of adjacent frequency resources over aplurality of adjacent time resources.

Clause 2. The method of Clause 1, wherein the group of RACH resourcescorresponds to a plurality of RACH occasions.

Clause 3. The method of Clause 2, wherein each RACH occasion of theplurality of RACH occasions is transmitted through a same transmissionantenna port of the UE as remaining RACH occasions of the plurality ofRACH occasions.

Clause 4. The method of any of Clauses 2 and 3, wherein each RACHoccasion of the plurality of RACH occasions is spatially transmitquasi-collocated with remaining RACH occasions of the plurality of RACHoccasions, has a same transmission power as the remaining RACH occasionsof the plurality of RACH occasions, has a same timing as the remainingRACH occasions of the plurality of RACH occasions, or any combinationthereof.

Clause 5. The method of Clause 4, wherein the same transmission power isa transmission power associated with a first RACH occasion of theplurality of RACH occasions or a maximum transmission power across allof the plurality of RACH occasions.

Clause 6. The method of any of Clauses 2-5, wherein only RACH occasionswithin a same RACH slot are assumed to be transmitted on the sameantenna port.

Clause 7. The method of any of Clauses 2-6, wherein only RACH occasionswithin RACH slots of a same FR1 subframe or a 60 kHz FR2 slot areassumed to be transmitted on the same antenna port.

Clause 8. The method of any of Clauses 2-7, further comprising:receiving an index value for each RACH occasion of the plurality of RACHoccasions.

Clause 9. The method of any of Clauses 2-7, further comprising:receiving an index value for a first RACH occasion of the plurality ofRACH occasions; and receiving a pattern of the plurality of RACHoccasions.

Clause 10. The method of Clause 9, wherein the association between theSRS resource or SRS resource set and the group of RACH resourcescomprises an association between the SRS resource or SRS resource setand the index value for the first RACH occasion.

Clause 11. The method of any of Clauses 2-10, further comprising:receiving one RACH preamble index for all RACH occasions of theplurality of RACH occasions.

Clause 12. The method of any of Clauses 2-10, further comprising:receiving one RACH preamble index for each RACH occasion of theplurality of RACH occasions.

Clause 13. The method of any of Clauses 2-10, further comprising:receiving a plurality of RACH preamble indexes for the plurality of RACHoccasions; and selecting one of the plurality of RACH preamble indexesfor each RACH occasion of the plurality of RACH occasions.

Clause 14. The method of any of Clauses 2-13, wherein at least one RACHoccasion of the plurality of RACH occasions is shared betweenpositioning and initial access.

Clause 15. The method of Clause 14, wherein the at least one RACHoccasion being shared between positioning and initial access isdifferentiated based on a RACH preamble index and/or a RACHconfiguration index associated with the at least one RACH occasion.

Clause 16. The method of any of Clauses 14 and 15, wherein the UEincludes an indication in the group of RACH signals that the at leastone RACH occasion is being shared between positioning and initialaccess.

Clause 17. The method of any of Clauses 1-16, wherein all RACH resourcesof the group of RACH resources has the same RACH format.

Clause 18. The method of any of Clauses 1-17, wherein the first statecomprises an RRC connected state.

Clause 19. The method of any of Clauses 1-18, wherein obtaining theassociation comprises: receiving the association during the first state,or determining the association.

Clause 20. The method of any of Clauses 1-19, further comprising:receiving a configuration that the group of RACH resources can be usedfor positioning.

Clause 21. The method of any of Clauses 1-20, wherein the plurality offrequency resources comprises a plurality of PRBs.

Clause 22. The method of Clause 21, wherein the single time resourcecomprises a symbol.

Clause 23. The method of any of Clauses 21 and 22, wherein the pluralityof adjacent time resources comprises a plurality of adjacent symbols ora plurality of adjacent slots.

Clause 24. The method of any of Clauses 1-23, wherein the plurality ofadjacent time resources are not separated by gaps, or are separated bygaps shorter than a threshold amount of time.

Clause 25. The method of Clause 24, wherein the threshold amount of timeis such that no other channel can be transmitted during the gaps.

Clause 26. The method of any of Clauses 1-25, wherein the transmissionproperties comprise: an uplink spatial transmit filter of the SRSresource or SRS resource set, a path-loss reference resource of the SRSresource or SRS resource set, a path-loss estimate of the SRS resourceor SRS resource set, a transmission power estimate of the SRS resourceor SRS resource set, a transmission timing of the SRS resource or SRSresource set, an SCS of the SRS resource or SRS resource set, a durationof the SRS resource or SRS resource set, a transmission bandwidth of theSRS resource or SRS resource set, or any combination thereof.

Clause 27. The method of any of Clauses 1-26, wherein the group of RACHsignals comprises a group of RACH Message A, a group of RACH Message 1,a group of RACH Message 3, a group of DMRS of a RACH Message A, or agroup of DMRS of a RACH Message 3.

Clause 28. The method of any of Clauses 1-27, wherein the UE is engagedin a positioning session with the TRP.

Clause 29. The method of Clause 28, wherein the positioning sessioncomprises an uplink time difference of arrival (UTDOA) session, amulti-RTT session, or an AoA session.

Clause 30. A method of wireless communication performed by a TRP,comprising: receiving, from a UE, an SRS on a an SRS resource or SRSresource set; and receiving, from the UE, a group of RACH signals havingtransmission properties based on an association between the SRS resourceor SRS resource set and a group of RACH resources on which the group ofRACH signals were received, wherein the group of RACH resources spans aplurality of adjacent frequency resources over a single time resource,or the group or RACH resources spans the plurality of adjacent frequencyresources over a plurality of adjacent time resources.

Clause 31. The method of Clause 30, wherein the TRP is engaged in apositioning session with the UE, the method further comprising:performing a positioning measurement of the group of RACH signals.

Clause 32. The method of any of Clauses 30 and 31, wherein the group ofRACH resources corresponds to a plurality of RACH occasions.

Clause 33. The method of Clause 32, wherein each RACH occasion of theplurality of RACH occasions is transmitted through a same transmissionantenna port of the UE as remaining RACH occasions of the plurality ofRACH occasions.

Clause 34. The method of any of Clauses 32 and 33, wherein each RACHoccasion of the plurality of RACH occasions is spatially transmitquasi-collocated with remaining RACH occasions of the plurality of RACHoccasions, has a same transmission power as the remaining RACH occasionsof the plurality of RACH occasions, has a same timing as the remainingRACH occasions of the plurality of RACH occasions, or any combinationthereof.

Clause 35. The method of Clause 34, wherein the same transmission poweris a transmission power associated with a first RACH occasion of theplurality of RACH occasions or a maximum transmission power across allof the plurality of RACH occasions.

Clause 36. The method of any of Clauses 32-35, wherein only RACHoccasions within a same RACH slot are assumed to be transmitted on thesame antenna port.

Clause 37. The method of any of Clauses 32-36, wherein only RACHoccasions within RACH slots of a same FR1 subframe or a 60 kHz FR2 slotare assumed to be transmitted on the same antenna port.

Clause 38. The method of any of Clauses 32-37, further comprising:transmitting, to the UE, an index value for each RACH occasion of theplurality of RACH occasions.

Clause 39. The method of any of Clauses 32-37, further comprising:transmitting, to the UE, an index value for a first RACH occasion of theplurality of RACH occasions; and transmitting, to the UE, a pattern ofthe plurality of RACH occasions.

Clause 40. The method of Clause 39, wherein the association between theSRS resource or SRS resource set and the group of RACH resourcescomprises an association between the SRS resource or SRS resource setand the index value for the first RACH occasion.

Clause 41. The method of any of any of Clauses 32-40, furthercomprising: transmitting, to the UE, one RACH preamble index for allRACH occasions of the plurality of RACH occasions.

Clause 42. The method of any of Clauses 32-40, further comprising:transmitting, to the UE, one RACH preamble index for each RACH occasionof the plurality of RACH occasions.

Clause 43. The method of any of Clauses 32-40, further comprising:transmitting, to the UE, a plurality of RACH preamble indexes for theplurality of RACH occasions to configure the UE to select one of theplurality of RACH preamble indexes for each RACH occasion of theplurality of RACH occasions.

Clause 44. The method of any of Clauses 32-43, wherein at least one RACHoccasion of the plurality of RACH occasions is shared betweenpositioning and initial access.

Clause 45. The method of Clause 44, wherein the at least one RACHoccasion being shared between positioning and initial access isdifferentiated based on a RACH preamble index and/or a RACHconfiguration index associated with the at least one RACH occasion.

Clause 46. The method of any of Clauses 44 and 45, wherein the UEincludes an indication in the group of RACH signals that the at leastone RACH occasion is being shared between positioning and initialaccess.

Clause 47. The method of any of Clauses 30-46, wherein all RACHresources of the group of RACH resources has the same RACH format.

Clause 48. The method of any of Clauses 30-47, wherein the first statecomprises an RRC connected state.

Clause 49. The method of any of Clauses 30-48, further comprising:transmitting the association to the UE.

Clause 50. The method of any of Clauses 30-49, further comprising:transmitting, to the UE, a configuration that the group of RACHresources can be used for positioning.

Clause 51. The method of any of Clauses 30-50, wherein the plurality offrequency resources comprises a plurality of PRBs.

Clause 52. The method of Clause 51, wherein the single time resourcecomprises a symbol.

Clause 53. The method of any of Clauses 51 and 52, wherein the pluralityof adjacent time resources comprises a plurality of adjacent symbols ora plurality of adjacent slots.

Clause 54. The method of any of Clauses 30-53, wherein the plurality ofadjacent time resources are not separated by gaps, or are separated bygaps shorter than a threshold amount of time.

Clause 55. The method of Clause 54, wherein the threshold amount of timeis such that no other channel can be transmitted during the gaps.

Clause 56. The method of any of Clauses 30-55, wherein the transmissionproperties comprise: an uplink spatial transmit filter of the SRSresource or SRS resource set, a path-loss reference resource of the SRSresource or SRS resource set, a path-loss estimate of the SRS resourceor SRS resource set, a transmission power estimate of the SRS resourceor SRS resource set, a transmission timing of the SRS resource or SRSresource set, an SCS of the SRS resource or SRS resource set, a durationof the SRS resource or SRS resource set, a transmission bandwidth of theSRS resource or SRS resource set, or any combination thereof.

Clause 57. The method of any of Clauses 30-56, wherein the group of RACHsignals comprises a group of RACH Message A, a group of RACH Message 1,a group of RACH Message 3, a group of DMRS of a RACH Message A, or agroup of DMRS of a RACH Message 3.

Those of skill in the art will appreciate that information and signalsmay be represented using any of a variety of different technologies andtechniques. For example, data, instructions, commands, information,signals, bits, symbols, and chips that may be referenced throughout theabove description may be represented by voltages, currents,electromagnetic waves, magnetic fields or particles, optical fields orparticles, or any combination thereof.

Further, those of skill in the art will appreciate that the variousillustrative logical blocks, modules, circuits, and algorithm stepsdescribed in connection with the aspects disclosed herein may beimplemented as electronic hardware, computer software, or combinationsof both. To clearly illustrate this interchangeability of hardware andsoftware, various illustrative components, blocks, modules, circuits,and steps have been described above generally in terms of theirfunctionality. Whether such functionality is implemented as hardware orsoftware depends upon the particular application and design constraintsimposed on the overall system. Skilled artisans may implement thedescribed functionality in varying ways for each particular application,but such implementation decisions should not be interpreted as causing adeparture from the scope of the present disclosure.

The various illustrative logical blocks, modules, and circuits describedin connection with the aspects disclosed herein may be implemented orperformed with a general purpose processor, a DSP, an ASIC, an FPGA, orother programmable logic device, discrete gate or transistor logic,discrete hardware components, or any combination thereof designed toperform the functions described herein. A general purpose processor maybe a microprocessor, but in the alternative, the processor may be anyconventional processor, controller, microcontroller, or state machine. Aprocessor may also be implemented as a combination of computing devices,e.g., a combination of a DSP and a microprocessor, a plurality ofmicroprocessors, one or more microprocessors in conjunction with a DSPcore, or any other such configuration.

The methods, sequences and/or algorithms described in connection withthe aspects disclosed herein may be embodied directly in hardware, in asoftware module executed by a processor, or in a combination of the two.A software module may reside in random access memory (RAM), flashmemory, read-only memory (ROM), erasable programmable ROM (EPROM),electrically erasable programmable ROM (EEPROM), registers, hard disk, aremovable disk, a CD-ROM, or any other form of storage medium known inthe art. An example storage medium is coupled to the processor such thatthe processor can read information from, and write information to, thestorage medium. In the alternative, the storage medium may be integralto the processor. The processor and the storage medium may reside in anASIC. The ASIC may reside in a user terminal (e.g., UE). In thealternative, the processor and the storage medium may reside as discretecomponents in a user terminal.

In one or more example aspects, the functions described may beimplemented in hardware, software, firmware, or any combination thereof.If implemented in software, the functions may be stored on ortransmitted over as one or more instructions or code on acomputer-readable medium. Computer-readable media includes both computerstorage media and communication media including any medium thatfacilitates transfer of a computer program from one place to another. Astorage media may be any available media that can be accessed by acomputer. By way of example, and not limitation, such computer-readablemedia can comprise RAM, ROM, EEPROM, CD-ROM or other optical diskstorage, magnetic disk storage or other magnetic storage devices, or anyother medium that can be used to carry or store desired program code inthe form of instructions or data structures and that can be accessed bya computer. Also, any connection is properly termed a computer-readablemedium. For example, if the software is transmitted from a website,server, or other remote source using a coaxial cable, fiber optic cable,twisted pair, digital subscriber line (DSL), or wireless technologiessuch as infrared, radio, and microwave, then the coaxial cable, fiberoptic cable, twisted pair, DSL, or wireless technologies such asinfrared, radio, and microwave are included in the definition of medium.Disk and disc, as used herein, includes compact disc (CD), laser disc,optical disc, digital versatile disc (DVD), floppy disk and Blu-ray discwhere disks usually reproduce data magnetically, while discs reproducedata optically with lasers. Combinations of the above should also beincluded within the scope of computer-readable media.

While the foregoing disclosure shows illustrative aspects of thedisclosure, it should be noted that various changes and modificationscould be made herein without departing from the scope of the disclosureas defined by the appended claims. The functions, steps and/or actionsof the method claims in accordance with the aspects of the disclosuredescribed herein need not be performed in any particular order.Furthermore, although elements of the disclosure may be described orclaimed in the singular, the plural is contemplated unless limitation tothe singular is explicitly stated.

1. A method of wireless communication performed by a user equipment(UE), comprising: receiving, during a first state, a configuration of asounding reference signal (SRS) resource or SRS resource set; obtainingan association between the SRS resource or SRS resource set and a groupof random access channel (RACH) resources; and transmitting, whileoutside the first state, a group of RACH signals using transmissionproperties based on the association between the SRS resource or SRSresource set and the group of RACH resources, wherein the group of RACHresources spans a plurality of adjacent frequency resources over asingle time resource, or the group or RACH resources spans the pluralityof adjacent frequency resources over a plurality of time resources. 2.The method of claim 1, wherein the group of RACH resources correspondsto a plurality of RACH occasions.
 3. The method of claim 2, wherein:each RACH occasion of the plurality of RACH occasions is transmittedthrough a same transmission antenna port of the UE as remaining RACHoccasions of the plurality of RACH occasions, or each RACH occasion ofthe plurality of RACH occasions is spatially transmit quasi-co-locatedwith remaining RACH occasions of the plurality of RACH occasions, has asame transmission power as the remaining RACH occasions of the pluralityof RACH occasions, has a same timing as the remaining RACH occasions ofthe plurality of RACH occasions, or any combination thereof. 4.(canceled)
 5. The method of claim 3, wherein the same transmission poweris a transmission power associated with a first RACH occasion of theplurality of RACH occasions or a maximum transmission power across allof the plurality of RACH occasions.
 6. The method of claim 2, whereinonly RACH occasions within a same RACH slot are assumed to betransmitted on the same antenna port.
 7. (canceled)
 8. The method ofclaim 2, further comprising: receiving an index value for each RACHoccasion of the plurality of RACH occasions.
 9. The method of claim 2,further comprising: receiving an index value for a first RACH occasionof the plurality of RACH occasions; and receiving a pattern of theplurality of RACH occasions.
 10. The method of claim 9, wherein theassociation between the SRS resource or SRS resource set and the groupof RACH resources comprises an association between the SRS resource orSRS resource set and the index value for the first RACH occasion. 11.The method of claim 2, further comprising: receiving one RACH preambleindex for all RACH occasions of the plurality of RACH occasions.
 12. Themethod of claim 2, further comprising: receiving one RACH preamble indexfor each RACH occasion of the plurality of RACH occasions.
 13. Themethod of claim 2, further comprising: receiving a plurality of RACHpreamble indexes for the plurality of RACH occasions; and selecting oneof the plurality of RACH preamble indexes for each RACH occasion of theplurality of RACH occasions.
 14. The method of claim 2, wherein at leastone RACH occasion of the plurality of RACH occasions is shared betweenpositioning and initial access.
 15. The method of claim 14, wherein theat least one RACH occasion being shared between positioning and initialaccess is differentiated based on a RACH preamble index and/or a RACHconfiguration index associated with the at least one RACH occasion. 16.The method of claim 14, wherein the UE includes an indication in thegroup of RACH signals that the at least one RACH occasion is beingshared between positioning and initial access.
 17. (canceled)
 18. Themethod of claim 1, wherein: the first state comprises a radio resourcecontrol (RRC) connected state, and the UE being outside the first statecomprises the UE being in an RCC idle or RRC inactive state.
 19. Themethod of claim 1, wherein obtaining the association comprises:receiving the association during the first state, or determining theassociation.
 20. The method of claim 1, further comprising: receiving aconfiguration that the group of RACH resources can be used forpositioning.
 21. The method of claim 1, wherein the plurality of timeresources comprises a plurality of adjacent time resources.
 22. Themethod of claim 21, wherein: the plurality of frequency resourcescomprises a plurality of physical resource blocks (PRBs), the singletime resource comprises a symbol, and the plurality of adjacent timeresources comprises a plurality of adjacent symbols or a plurality ofadjacent slots.
 23. The method of claim 21, wherein: time resource ofthe plurality of adjacent time resources are not separated by gaps, orare separated by gaps shorter than a threshold amount of time, and thethreshold amount of time is such that no other channel can betransmitted during the gaps.
 24. The method of claim 1, wherein thetransmission properties comprise: an uplink spatial transmit filter ofthe SRS resource or SRS resource set, a path-loss reference resource ofthe SRS resource or SRS resource set, a path-loss estimate of the SRSresource or SRS resource set, a transmission power estimate of the SRSresource or SRS resource set, a transmission timing of the SRS resourceor SRS resource set, a subcarrier spacing (SCS) of the SRS resource orSRS resource set, a duration of the SRS resource or SRS resource set, atransmission bandwidth of the SRS resource or SRS resource set, or anycombination thereof.
 25. The method of claim 1, wherein the group ofRACH signals comprises a group of RACH Message A, a group of RACHMessage 1, a group of RACH Message 3, a group of demodulation referencesignal (DMRS) of a RACH Message A, or a group of DMRS of a RACH Message3.
 26. (canceled)
 27. (canceled)
 28. A method of wireless communicationperformed by a transmission-reception point (TRP), comprising:receiving, from a user equipment (UE), a sounding reference signal (SRS)on an SRS resource or SRS resource set; and receiving, from the UE, agroup of random access channel (RACH) signals having transmissionproperties based on an association between the SRS resource or SRSresource set and a group of RACH resources on which the group of RACHsignals were received, wherein the group of RACH resources spans aplurality of adjacent frequency resources over a single time resource,or the group or RACH resources spans the plurality of adjacent frequencyresources over a plurality of time resources.
 29. The method of claim28, wherein the TRP is engaged in a positioning session with the UE, themethod further comprising: performing a positioning measurement of thegroup of RACH signals.
 30. The method of claim 28, wherein the group ofRACH resources corresponds to a plurality of RACH occasions.
 31. Themethod of claim 30, wherein: each RACH occasion of the plurality of RACHoccasions is transmitted through a same transmission antenna port of theUE as remaining RACH occasions of the plurality of RACH occasions, oreach RACH occasion of the plurality of RACH occasions is spatiallytransmit quasi-co-located with remaining RACH occasions of the pluralityof RACH occasions, has a same transmission power as the remaining RACHoccasions of the plurality of RACH occasions, has a same timing as theremaining RACH occasions of the plurality of RACH occasions, or anycombination thereof. 32-44. (canceled)
 45. The method of claim 28,wherein all RACH resources of the group of RACH resources has the sameRACH format.
 46. The method of claim 28, wherein the first statecomprises a radio resource control (RRC) connected state.
 47. (canceled)48. The method of claim 28, further comprising: transmitting, to the UE,a configuration that the group of RACH resources can be used forpositioning.
 49. The method of claim 28, wherein the plurality of timeresources comprises a plurality of adjacent time resources. 50.(canceled)
 51. (canceled)
 52. The method of claim 28, wherein thetransmission properties comprise: an uplink spatial transmit filter ofthe SRS resource or SRS resource set, a path-loss reference resource ofthe SRS resource or SRS resource set, a path-loss estimate of the SRSresource or SRS resource set, a transmission power estimate of the SRSresource or SRS resource set, a transmission timing of the SRS resourceor SRS resource set, a subcarrier spacing (SCS) of the SRS resource orSRS resource set, a duration of the SRS resource or SRS resource set, atransmission bandwidth of the SRS resource or SRS resource set, or anycombination thereof.
 53. The method of claim 28, wherein the group ofRACH signals comprises a group of RACH Message A, a group of RACHMessage 1, a group of RACH Message 3, a group of demodulation referencesignal (DMRS) of a RACH Message A, or a group of DMRS of a RACH Message3.
 54. A user equipment (UE), comprising: a memory; at least onetransceiver; and at least one processor communicatively coupled to thememory and the at least one transceiver, the at least one processorconfigured to: receive, during a first state, a configuration of asounding reference signal (SRS) resource or SRS resource set; obtain anassociation between the SRS resource or SRS resource set and a group ofrandom access channel (RACH) resources; and transmit, while outside thefirst state, a group of RACH signals using transmission properties basedon the association between the SRS resource or SRS resource set and thegroup of RACH resources, wherein the group of RACH resources spans aplurality of adjacent frequency resources over a single time resource,or the group or RACH resources spans the plurality of adjacent frequencyresources over a plurality of time resources. 55-80. (canceled)
 81. Atransmission-reception point (TRP), comprising: a memory; at least onetransceiver; and at least one processor communicatively coupled to thememory and the at least one transceiver, the at least one processorconfigured to: receive, from a user equipment (UE), a sounding referencesignal (SRS) on an SRS resource or SRS resource set; and receive, fromthe UE, a group of random access channel (RACH) signals havingtransmission properties based on an association between the SRS resourceor SRS resource set and a group of RACH resources on which the group ofRACH signals were received, wherein the group of RACH resources spans aplurality of adjacent frequency resources over a single time resource,or the group or RACH resources spans the plurality of adjacent frequencyresources over a plurality of time resources. 82-106. (canceled)
 107. Auser equipment (UE), comprising: means for receiving, during a firststate, a configuration of a sounding reference signal (SRS) resource orSRS resource set; means for obtaining an association between the SRSresource or SRS resource set and a group of random access channel (RACH)resources; and means for transmitting, while outside the first state, agroup of RACH signals using transmission properties based on theassociation between the SRS resource or SRS resource set and the groupof RACH resources, wherein the group of RACH resources spans a pluralityof adjacent frequency resources over a single time resource, or thegroup or RACH resources spans the plurality of adjacent frequencyresources over a plurality of time resources.
 108. (canceled) 109.(canceled)
 110. (canceled)